Rahmu: Just to give you insight on my experience with ICS:
I bought the Note running Gingerbread. Day after day I hated it. It was a bit slow, sometimes laggy, and after like 2 months of filling up my phone with apps and running much in the background, used to often take a few seconds to return back to the home screen after I pressed the menu button from an app.
We waited for the "lovely" Samsung to provide us with the Ice Cream Sandwich updates. They postponed the Galaxy Note updates to Q2 2012. Also, for the Galaxy S2 i9100G (which started shipping since late 2011), the ICS update started seeding only a week or two ago. Samsung is terribly late to upgrading their phones to ICS (and who isn't? most are).
So I thought: let's install a well-supported, stable, ICS-based ROM on my phone. I tried imilka's AOSP v8 ROM on my Note. It used Samsung drivers ripped from the Chinese Note ICS ROM leak. The ROM was speedy and perfectly smooth (will get to that point later), but it had its own share of problems: lack of SD card mounting, freezing when using mass storage mode, etc... so I replaced it with ICS stunner, which is based on AOSP too (similar). These problems were solved. Now the point:
ICS supports GPU hardware acceleration, as you may know. Gingerbread uses an older method, similar to GDI, for rendering screen, which depends a lot on CPU.
http://en.wikipedia.org/wiki/Graphics_Device_Interface
From the article: "Simple games that do not require fast graphics rendering use GDI. However, GDI is relatively hard to use for advanced animation, and lacks a notion for synchronizing with individual video frames in the video card, lacks hardware rasterization for 3D, etc. Modern games usually use DirectX or OpenGL instead, which let programmers exploit the features of modern hardware."
iOS, if I'm not mistaken, has always used OpenGL. This is why compared to Android, it is almost always smoother.
ICS was not targeted to offer major new features. Most of its importance lies in under-the-hood tweaks / bug-fixes. Off the top of my head, ICS has native USB OTG support (mounting USB drives on your phone using the an OTG microUSB connector) and native gamepad support. Both of these are crucial to me, but may not seem important to you. Feature additions are "planned for v5.0 Jellybean", which should debut a few months after ICS. (Manufacturers, let's get ICS to all those devices first, shall we? Galaxy Nexus, I love you.)
As for the point you made: If it does the job, that's what matters". Gingerbread MAY do the job, but it does not necessarily do it efficiently. I'm guessing that since GPUs are more efficient / performance relative to CPUs related to certain graphical workloads, UI rendering will require less power, and the battery life may be boosted (though the UI is not the most intensive thing you can do on a phone, of course).
About benchmarks: Benchmarks are used to compare, as an absolute, the performance of two products regardless of the user experience. If I am seeking a phone to put a custom ROM on, and do not care about the software it ships with, then I would really take a close look at benchmarks. If one games on Android, GPU performance is an important point.
There is something I do not get, though. Quad core CPUs on phones. I mean, of course it can be used eventually, but the point is that a tough workload on a phone may be more related to the GPU in the phone. A game, for example. The only workload i can think of that really depends on the CPU alone is ZIP compression (are you going to be compressing ZIP files on your phone?). The phone seems to already be heading the way the PC is heading. More powerful GPUs and less powerful, more efficient CPUs.
Apple seems to have realized that, and has shipped its iPhone 4S with a dual-core @800MHz (which it believes is enough, I guess), and a very powerful GPU that competes with the Tegra 3 GPU! Meaning it beat the S2's GPU, and by a respectable margin. If you're going to be running anything intensive, it will be a game, and the 4S has got you covered there.
Qualcomm has done it right too. It has produced the dual core Krait S4, which is more powerful than the Quad core Cortex A9 (used in the One X and the S3). Up till now, it's been demonstrated to be more powerful than the One X's CPU. For the S3, we shall see.
The dual core is more efficient at load since it's on 28nm transistors (Tegra 3 CPU 45nm, S3 32nm). At idle, it's definitely more power efficient (in deep sleep, a phone does not need a high CPU frequency or voltage. Both can greatly be undervolted. 28nm vs 45nm takes its effect.
The only scenario where I could imagine multi-core processing would kick off is to move to even more cores. Smaller, less powerful cores, greatly undervolted, would reduce power consumption (power increases with the square of voltage). This requires software which allocated its resources over a large number of cores. It's similar to GPUs, which have stream processors (you could call them cores. Nvidia does.) The disadvantage, however, is that CPUs would move towards GPUs, which means you need parallel workloads to utilize the whole chip.
The point of design is interesting. HTC One X had to sacrifice a removeable battery to provide its unibody design that is able to withstand (insert any natural disaster here). It has also removed its microSD slot (I don't know why, it could have been included on the side). The advantage, however, is that it looks fantastic.
But me, I would rather have the removeable battery, and microSD slot, even if it means a cheap plastic battery door (no glass, thank you). I guess I can replace it with an aluminum door, if I like that.
Samsung's phones have bog-standard design, but their hardware is top-notch. This is a fact that nobody can dismiss. I see these phones as better fit for custom ROMs, compared to HTC which already provide a unified experience with the Sense UI (something you may hate too, on the flip side).
I see it this way: as long as I can grab it, work with it without discomfort, and ships with the hardware I want, I am willing to go through a headache to tune software to perfection, and run my dream ROM on there. But hey, that's just me.
I deeply respect the achievements that Apple have made with the iPhone, but this is the problem: its hardware is not always top notch, its software is excellent, but I cannot fine tune it. I have to take it or leave it. Isn't this Apple's policy with introducing a single (albeit hugely successful phone) once per year? Aren't they missing out on people who enjoy screens greater than 3.5"? One poll said that people seem to have a preference of screen larger than 4+ (can't find the link now). Apple seem to be missing out on those people if they don't introduce a 4" iPhone 5 (then existing iPhone users would complicate that it's large, but you just can't please everybody). Now their idea of an iPad mini (if the rumors are true) is a good move as I see it.
Samsung: ahh Samsung. I think they are heading the right direction / they did it right with the S3. They are improving software, which is their focus now (more than hardware, it seems). Just look at Smart Stay, Smart Alert, Pop up play, S-Beam, etc... I could see myself using ALL of those, If I had an S3. Designed for humans is right. These are features which would not only make you go "WOW NICE!", they would be usable on a daily pattern. However, S-Beam reminds me of bluetooth sharing on iPhone. It's limited to usage between S3's only. We shall see what happens when NFC becomes even more common. Maybe there will be an open standard for NFC authentication and sharing over WiFi? Bluetooth 4.0 + HS uses BT for authentication and WiFi for data transfer (they did it right).
Something else these new phones have to fix is input lag. Touchscreens need to have latencies below 100ms now. It's time. This would be an incredible achievement. Microsoft have demonstrated a 1ms lag touchscreen (layer only, not a color touchscreen yet), but we shall see how long it takes.
About RAM: For example, ICS Stunner ROM has a setting called Euphoria Control. It can control so much aspects of the phone (too long to go into here), but the idea is that it offers settings for adjusting how conservative the phone is with RAM). The default is leaving 80MB free out of 800MB. That's great, I guess. You can also improve scrolling performance but for more RAM consumption, in an adjacent setting.
And yes, the difference between back and "exit" on GB is that exit actually terminates the app, while back runs it in the background. I am guessing that the major drain on battery life comes not from memory the apps are consuming, but rather, CPU and GPU cycles (think a game). I have realized that if I turn on a gaming app like FPSe (PS1 emulator on Android), press back and send it to background, or lock the phone, it will still run. This is evidenced by the continuous heat being output, and the extremely fast battery drain. I don't know, but maybe apps can be coded to have a sleep mode if they are graphically intensive. Maybe this can solve many battery drain problems. (My Desktop GPU load goes to 0% when I minimize a game (maybe because they use DirectX9/10/11 / OpenGL while OpenGL ES has a limiation? IDK).
About the perfect scenario of everything being loaded into RAM, we either need storage that is as fast as RAM (future SSDs, holographic storage, memristors, anyone?) or storage that is fast enough to boot from without taking ages, or delayed app startup. This would provide the smoothest experience, if frequently used apps were to boot with the phone, and it had enough RAM (hello LG Optimus LTE2, 2GB of RAM!).
I/O-performance evolves at a much slower pace than raw CPU and GPU performance. Why? We need a breakthrough. It's as if they don't care how fast on-board NAND is. (Why?? I can't wait ages to copy something to my phone. I will have to resort to getting a high-speed microSD).
Just my 2 cents (grands?). Did I miss anything?
