I have an AWU1, and when the 2 came out, I basically ignored it as there didn't seem to be many upgrades. This year, they released the black color and didn't release new hardware - but the software update came with a bunch of little upgrades that were exclusive to the AWU2. Now, the difference is a big bigger than I thought:
AWU2 Upgrades over AWU1 (new ones in bold):
Screen Brightness - 3000 nits vs 2000 nits
Sleep apnea tracking
SI SiP Chip
Double tap chester
On-device Siri
Precision finding for iPhone
Media playback
Double tap is a useful feature, and many are saying media playback is sleeper great add. There is one downgrade however - blood oxygen tracking
Basically, it seems more reasonable to upgrade to an AWU2 now (especially if you are getting the black for a color change) than it did a year ago...
AWU2 Upgrades over AWU1 (new ones in bold):
Screen Brightness - 3000 nits vs 2000 nits
Sleep apnea tracking
SI SiP Chip
Double tap chester
On-device Siri
Precision finding for iPhone
Media playback
Double tap is a useful feature, and many are saying media playback is sleeper great add. There is one downgrade however - blood oxygen tracking
Basically, it seems more reasonable to upgrade to an AWU2 now (especially if you are getting the black for a color change) than it did a year ago...