Beats me, as I only ran them through a couple quests. For purposes of DR, the Pure Barb would probably come out ahead in the end, but the Fighter/Barb gish would have the feats to help with dps. In the long run, I'm certain that choosing feats differently for dps rather than DR would be more advantageous.

I like creating characters. It's always been my favorite aspect of RPGs. I can spend a week rolling characters for Wizardry 7.

Barb/Sorc actually has no common ground, so I think it'd end up being a bit weaker in the long run unless you built it perfectly. Maybe do enough Sorc to get Reconstruction, and have a self-reliant, self-buffed Melee character. But I'd not want to push that through the early levels.