Overall I'm really happy, coming from stock 1.5 it to the official Sense 2.1 update it seems a lot quicker. The Android devs talked about introducing lower priority for garbage collection in 2.1, and it seems to help, less judders when scrolling lists etc.
I'm loving the new weather animations when you unlock your homescreen. The wispy floating clouds are awesome!
And of course, there is the major improvement to the colour support, no more dithering or banding, the colours are sharp and clear.
One major pain, though, I swear the the volume rocker used to change the System volume when on the homescreen. Now it only changes the Ringer volume, so I have to lower the ringer, the notifications, etc, individually rather than all in one go. There doesnt seem to be a way to override what the volume rocker controls.
A new bug, when you open an sms message conversion and click in the new message area, the messages above dont shift up enough. Hence the keyboard is obscuring the last message, you cant see what you are replying to. If you cancel that, then click again to write a new message it correctly shifts the messages so the last one can be seen. This is a new bug, it used to shift them correctly in all cases.
Battery was seriously killed yesterday after the update (which understandably required a LOT of processing) and trying out all the new features, but today the drain seems just the same as 1.5.
I would also like to know if there is an APK for friendstream, live wallpapers, 3d gallery etc..