I have been running this for close to a week now. I am suprised that there are so few comments on this thread.
I did the upgrade from version 141 which i was having quite abit of issues with. It was slow to respond, the media player would mute all the time and it leaked memory like a rusty bucket!!
This new version is a whole lot better. Besides the new open/close effects (which are abit jittery anyway) the phone seems to be a whole lot more responsive. Battery life is good, signal strength is great menus are quick to open as is the lock/unlock button.
My favorite thing though is the improvement to the media player. It looks the same but it works so much better!! The volume no longer suddenly mutes, and when you get a call it mutes then gose back to the correct volume. The slider button works much better when scrolling through videos/music tracks which is handy if you come back to a movie that you were watching. And my very favorite thing is that the overall volume when listening to music/videos is much improved!!
So over all after close to a week i can safly say this is indeed the best os so far. Also I have read alot about themes not running, so i kept the default theme for a few days. I was really missing my today screen so i tried the AppleBerry Classic with today and Weather support. It has been working perfectly!!
So in closing get this beta, you wont be dissapointed!