it's less stable if you make it less stable...
ie., you can want to build a brick house, so you start using bricks...then half way through once you laid down 90% of the bricks, you decide you can finish it off with hay bails....
does that make sense?
A lot of "legit" sources aren't really legit if they don't offer up the complete scenario to you...if they don't offer the full info...they are just posers
just take common sense and logic with you...
going 64bit drivers, make sure your hardware vendors have 64bit Vista drivers...and just check to see if any apps you have that aren't 64bit are 64bit friendly