Cyril wroteHad a question, so I thought I'd post it in the this specific topic:
I wanted to downgrade from OS Lion to Snow Leopard, I feel a major loss of speed with the upgrade.
Do you think with the updates things would go better?
Anyway, is downgrading a simple task? Will I loose some of my documents?
I think its too early to judge the first release of Lion (10.7), any initial release might have some stability problems. Today Apple released 10.7.1 upgrade, so I advise update Lion to 10.7.1 and see whether the loss of speed remains.
I found that 10.7.1 fixed the memory consumption issue, especially with Safari. At start up, Lion consumes only 1.4GB RAM, before update, it used to consume about 1.8GB. Also, Safari was going memory hungry! reaches about 850MB, now its about 350MB even in Full-Screen Mode. Most of the time I was running low on memory, reaching 10MB Free from 3GB!
If you want to downgrade to Snow Leopard, you need to make a TimeMachine backup, but you need first to format an external drive to Mac OS Extended (Journaled).
Next, bring the Snow Leopard Disk that came with your Mac, and format the existing Lion partition.
When the installation is finished, use Migration assistant to Migrate from a TimeMachine Backup.
This would keep your files as you left them before formatting Lion, but not 100% sure if Migration Assistant will consider a TimeMachine Backup as Lion or as Snow Leopard to restore it (i.e. restoring Lion to Snow Leopard might keep existing Lion features)
I used TimeMachine a lot, but didn't try downgrading to Snow Leopard and restoring files from Lion.