+ LED notification is absolutely rubbish.
My phone is next to my Hero today as the numbers are being ported and I just received an email to my Gmail. With the phone lying vertically under my screen I could barely see the flash from the Sensation (to the extent that I'd already missed one mail) whereas the Hero was flashing away in all it's beauty to let me know.
+ Phone rebooted when taking a photo.
I've only taken a few pics on here, but after taking one of the dog last night with the flash on, the phone instantly turned off and completely rebooted. Maybe it's a one off, but it definitely wasn't good! Will have to keep an eye out for this happening again.
+ Trace seems a bit hit and miss.
I used Swype on my Hero so am assuming I just need to learn how to use the new one. I'll have to work on that one myself although it may be a case of training the phone not to pick out the most obscure word possible when all I want is to spell "hello".
I haven't really used it enough to spot any others, but I'm intrigued as to what other issues people seem to be finding.
...and on a side note I'm really, really missing the trackball that's on my Hero. Selecting text is so sensitive and I keep catching the wrong bit. I feel quite sad letting the little guy go. He's served me so well!! It does feel like a toy now when I go back to it. Lo-res and chunky!