G0-T0 is good. I don't understand why everyone says he sucks. He's a good character if you get enough influence with him and he is always good in combat, especially against other droids, he has that ability to turn enemy droids into allies. In my last game, before I got Mandalore, I was running with HK-47 and G0-T0 all the time. I was kicking major arse as a consular with two super droids; unresistable force powers + a hail of shots from well upgraded blasters = dead enemies.
The best part about my game was that I didn't kill Zez-Kai El(sp?) on Nar Shadaa, but then I killed Vrook and Kavar so when I met Zez he was pissed at me.
Anyhow, in my next game I'm going to start as DS and be redeemed into the light side. I might kill Zez then spare the others, if I can.