I friend of mine got me OS X 10.7 P3, after reading the cool features and of course integrated FaceTime, I was interested in giving it a test drive. Before installing, I did some reading of user experiences and decided to do a clean install of Snow Leopard and then upgrade.
Here is the method I used on my MacBookPro (2008).
Installed clean 80GB hard disk
Booted and installed SnowLeopard DVD (hold down the C key and hit power)
Download 10.6.8 Combo update from Apple and install
Go to software update and install updates
install 10.7 P3 update (this is a App update)
Install apps I use.. Office 2011, Lotus Notes
I am not experiencing the same issues others are that updated from 10.7 P2 or from a system that started out with Leopard - SnowLeopard - 10.7, Maybe some issues with kexts or other software carried over from the later that causes issues with 10.7 P3.
If you want to see some of the new features OS 10.7 google it, looks like a great OS for us Mac users.