I was using Macnut R7 and was about to flash R9 but Team Whiskeys downloaded faster. The major difference between R9 and 7 is, wi fi calling, modem and working gps with some minor tweeks.
If that is true then my comparison won't be too far off.
The biggest difference between the too is that Team W is a near perfect leak of the official 2.2 rom and Eugene's has some mods like built lag fix and a modified version of T.W. which for the most part is better than stock (not perfect but better; in my opinion)
That should really be what makes you choose which one you want.
Secondary things to think about is that, whiskey roms are known for getting official ota's which is nice if you want to get the official with little work, but its still kinda glitchy and slower than Eugenes, but not in a bad way. If you are running stock without a lag fix then you won't notice much. Eugene's rom is highly modded and some stock things won't work like if you still have avatar on your sdcard, and since his is a port there are some remnants of I9000 and cappy things floating around that can throw you off. But it is less glitchy atm and too me looks better. It has a lightly themed Modified TW. But you can get and install that yourself if you want there is a link in the macnut thread.
Hope that helps. I'm Running tw's rom now but I'm going to check out R9.