Pros:
+Faster than vista
+Less RAM usage than Vista
+Boot time as fast as xp
+New Pins System
+Aero is more slick
+More accessible
Cons:
-Almost not security suite is working on it
-XP compatibility mode is a con, they could have done so much better
-uTorrent working very slow :|

so what did you like about it, and what did you not?

I'd rate it higher than XP which Vista wasn't. So it is true, W7 is what XP was to WMe
I would like to point to one thing... Windows 7 feels like faster but it is not ... based on many benchmarks I did, It performed almost same as vista... the difference is that the GUI is faster. I thought at the beginning It was something wrong with my pc but then I found also an article talking about the same thing :

http://www.nillabyte.com/blog.php?b=128

Utorrent working fine here 200KB/sec downloads .. If you are still having problems try this
Options > Preference > Advanced > Disk Cache
and remove checkmark next to the Enable caching of disk writes...



However, I still prefer XP, just MHO.
We have already tested it, haven't we? Same shit, just a different color.
a month later
Same shit, just a different color.
Nice description ;) :D Actually windows 7 didn't mean much to me even though it can be slightly better than the older disaster: Vista. I believe that the saying that Windows 7 is faster is just another myth that is part of Microsoft's marketing strategy to satisfy consumers "psychologically" towards the new product ;)
3 months later
hey guys. im currently using windows 7 professional, which i got from msdn (genuine products released sooner in msdn). windows 7 is faster than vista, way faster. not only gui, but disk and memory performance. look, benchmarks may give some decent results, but when it comes to real experience, windows 7 performs better than vista: vista is not even close to 7. iv noticed huge difference in games (C-Strike, NFS Undercover, Fallout 3, Crysis), and heavy software such as photoshop and video encoding.

what about microsoft's propaganda of selling more by saying 7 is faster: this is not true. the new product is truly faster. the only problem i found in windows 7 is software compatibility issues. windows 7 has this huge problem. this means a huge percentage of ur installed software wont work in 7. i had to update all my programs to meet the requirements. ecspecially when it came to antivirus. had to find a working antivirus the whole week.
Hey everyone,

I have been using 7 since Beta. I then tried RC, and now I have Ultimate 64-bit RTM through a competition I won online. It was about writing a technical article about new features in 7. Below is my article and this should explain to you why it is faster.

"Learning from Windows Vista, Microsoft was able to build on the great UI (User Interface) in Windows 7 while addressing the performance glitches Windows Vista suffered from.

One of the improvements that I really valued is the performance gain with multiple GDI (Graphics Device Interface) applications running simultaneously on mutli-core processors. In Windows Vista, the most frequent cause of hang-ups was when two applications were trying to access the graphics card at the same time. The GDI design in Windows Vista allowed a single application to hold a system-wide global lock. As a result, other applications trying to access the graphics card at the same time would get locked out and eventually the hang-ups would occur.

In order to solve the problem, the Windows 7 team re-architectured the internal synchronization mechanism and therefore reduced the lock contention and the memory footprint. Thus, a GDI application window visible on the desktop in Windows 7 consumes half the memory when compared to Windows Vista. Moreover, these improvements also resulted in a better rendering performance of GDI applications on multi-core processors.

The overall result was a more responsive experience."

As expected its faster.
Its good that Microsoft is going the rewriting core code route.
They have lots of stuff to rewrite, for example the DLL versioning system that made up 3/4 of the vista system folder size (like 8 gigs), and the install/uninstall system has to be rewritten into something adware/virus proof. For example like processes have a virtual memory space, software could have a virtual disk image, each software should have its own image of the disk, for example if it tries to modify a system file, it will look modified only for this particular software. I think the OSX software management system (if you can call it this way, since its just dropping a package in a folder) is simpler, and Im from the less is more school, so I consider it superior. The unix system is also good, and one of the smartest tricks that I read of, is giving each package its own username. The package will be installed under this username, all its files will have that username, and there is even no need to maintain a package db for install/uninstall, and more control over security.
But a total rewrite might be break backwards compatibility.