I've only noticed an appreciable difference so far with the popup menu (e.g. adding widgets or app/folder icons to desktop), but it certainly does the trick for that. I'll have to have more of a play and see how the rest of the performance and battery life holds up.
If it has been doing software rendering through the VM and CPU unnecessarily, it may well be the cause of my device feeling warmer than normal since the update and why battery life has gone down.
Edit: So far so good with performance boost, I can 'feel' it in the UI in a number of places; but it doesn't extend to (for example) video playback so probably UI related stuff only, though I do seem to have reclaimed a large amount of memory? I'd been suckerpunched down to about 120MB lately but now it's showing an easy 230-247MB free. Note that I only changed the debug.sf.hw parameter of build.prop and none of the other suggestions. Keyboard input also seems a lot more responsive, I can type out at a fairly quick speed and it seems like the keyboard is doing a good job of keeping up with me (aside from my clumsy mis-keys), whereas before it would feel more sluggish and drop keys I was sure I had pressed.