Let the hive mind of Engadget get that for you.
"I've found myself using my PC for a lot of conversations lately, and I'm also considering recording a podcast to share with anyone who will listen. There are tons of USB headset / microphones out there, and I'm hoping someone has some solid recommendations based on experience. I'll consider both headsets and standalone mics, by the way, but I'd like to keep the bill under $100 if possible. Help!"
The difference between 2.15.502.1 and 2.15.502.3 (besides a few MB) is additional AT&T branding and the adding "Task Manager" from HTC was rebranded to "X-Button". Besides the additional bloat that AT&T happily added the ROM feels smoother and snappier than the original ROM. There are quite a few changes that I like.