I PVP quite a lot on Space Slug. I would agree with the the original post, that the Republic Players tend to be better than the Imps when I play them in morning/early afternoon. In the evening, however, the odds adjust themselves and are just about 50/50.
As far as Ilum goes, I've won many more 1-1 encounters than I have lost, so I can't honestly say that I think individual skill is the main reason for the discrepancy.
I think that cooperation and complementary abilities may be the reason the Pubs do better. The smaller Pub population helps this, as Pubs will often find themselves in a group with the same people. As they group over and over with the same people they learn to operate better as a team.
- Snaggle