There are a bunch of threads about this. If you are running less than 6 clients, GB2 is the way to go. Since GB2 uses CC's it fights a lot better. Therefor killing faster and avoiding deaths lot more. I also find it gathers quicker than GB1.
I tried searching but so much came up from other threads of different topics that I gave up going thru the pages lol so I just decided to get a fresh up-to-date answer