I'd be very interested in your perspective here. Also have a MBP (2007) and have had all sorts of problems (including failed hard drive) since upgrade. I wouldn't change Lion on my mid-2011 MBA, but before I enroll onto iCloud, I am considering reverting back to SL on the MBP
My early 2008 MBP has been the single most trouble prone computer I have EVER owned. The only saving grace has been Apple's customer service past the warranty.
Apple's replaced the RAMx1, Main Logic Board x1, upper case x3, lower case x1, display x1, power supply x2, Superdrive x2. Hard drive's been replaced twice, by me. I know I'm forgetting some incidents.
I installed Lion on top of SL soon after release. It was an extremely unstable system. Graphical glitches, keyboard behavior, instability, etc, on top of many of the common bugs others have reported.
Recently, I did a clean install. Many of the issues are still there. I'm going to give it a week, then it's back to SL if I don't see improved stability. I have tried really hard to like Mission Control and other Lion behaviors but have come to the conclusion that it's a step back. I feel like one of my hands are tied with Lion, in the same way I feel when I step back to old versions of OS X.
If I do revert, I'll come back once the new features are fully baked.
Works fine on a clean install on an 2007 MB, primary user actually likes most of the new Lion features and never really used lost SL features so Lion is a net gain for her.