I dont know if Mp3 playing is better as I dont have a large library like you, but I am not a fan of this version at all. My rewinding and fast forwarding have become horrible as I start to fast forward but it sticks on the screen that I started at, leaving me guessing where I am at in the progress. Other then that I think they are doing alot underneath the skin of the code and I believe (no facts here just guessing) that we are going to see more added to this machine in what it can do (we now have sound effects!!!). I am curious to see if this version will stop my Auto delete when I record National Geographic HD. My wife has really been on me to get the in the womb, and I cant play it back.
Highlights for me
HD search results now show up first
Sound effects for invaild choices
and according to Earl the guide is now cached to the hard drive for 14 day guide after a reboot.