Right now the only thing you can go by are the differences in specs.
GN has non removable battery or SD card, rezound extended battery and cover are already available. advantage Rezound
GN is coming in two models - 16 gb internal and 32 gb internal. Rezound only has 16 gb internal and a 32 gb sd capacity. I'll bet you;ll pay more for that extra 16 gb in the GN than you will for a SD card.
Both 4g, wash
both 1 gb ram, wash
android 2.3 vs 4.0, advantage GN, although many of the individual advantages of ICS are available today as market apps that you can run on phones as far back as an Eris... Although with ICS being essentially developed specifically for the GN, that has to have some advantages
1.2 vs 1.5 ghz dual core processors, advantage Rezound
8 back and 2 front vs 5 back and 1.3 front camera resolution, advantage Rezound
Styling, I think is advantage GN. In my opinion, the Rezound is basically a rehashed design.
Display resoultion, wash
screen size 4.65 vs 4.3. This is a wash because the buttons for ICS are integrated into the screen. Well, it's a wash until Rezound gets ICS, then the Rezound has some redundant buttons on the front of the device.
I read the Rezound is supposed to have a barometer for local weather
The GN camera is supposed to be really slick. With no-lag and the smooth panorama, it could be nice.
Not sure what Beats is going to bring to Rezound, but I wouldn't mind a better quality external speaker.