Memory usage
Been using Vista (and yes flame away all you like, but I've had no issues other than drivers) for over 18 months now, and have found a few intriguing things.
Personal favourite has to be booting the machine, and dropping it to sleep again. Haven't yet figured out what’s not restarting (everything runs correctly, all services are still there etc), but you will regain between 20-30% free RAM back. And a bit of a performance improvement.
And Readyboost is also quiet interesting, depending on machine seen next to no change, up to 15% speed boost from it. Although this does confuse some users having a USB drive stuck in the back of the machine permanently.
Guess a lot does depend on what’s being run, how lazy the dev's were who made it when they just kept hacking things together and using code going back 10-20 years or so. Things progress, and really performance can't be really regained until backwards compatibility is dropped (yes I know the jokes here about Vista's compatibility).
As others have said above, this was the same with going from 2000 to XP, it was slower. And the jump from 98 to 2000, or from 95 to 98, it's always been so. Every time I upgraded my Mac (which makes a nice doorstop) yes, it got slower also. It's always happened, and always will. Adding more to something makes things bigger as odd as that may seem to many.
Great artical though. Anyhow, flame away :P