Just gotta point this out: Most transitions tweaks don't actually change performance at all - what they change is how quickly certain animations play, which, with the right combinations of visual effect, they make people feel things are going faster/better/smoother when they are actually the same.

What performance gains you get is setting rotation animations down to all zeroes, for instance (which isn't truly performance, but it cuts the time to rotate down... by, like, a barely perceptible difference from the transitions I was using beforehandc), and/or dropping the amount of iterations of "blur" on background stuff when a menu pops up, etc (which may or may not actually noticeably change anything performance wise, and unless you're pushing your device or catch it during heavy RAM/swap IO it shouldn't change anything, although I have noticed a slight purely psychological effect in that switching from more blur to significantly less or none [especially none] gives a perceived UI 'crispness' that seems to in turn give the illusion of graphical performance being better.)