It depends on the rest of the party.
If everyone else has a bunch of 16s and 18s and the like, and I've got a character I barely didn't throw away after 3 rolls, then my character will be less effective.
Reminds me of a game I'm in right now. I'm playing a bard, and the rest of the party consists of fighter-awesomes. Last time, we raided a thieves guild. I walked around with a wine glass in hand, occasionally listening at doors. I asked people to surrender so we didn't have to kill them.
But other than that, I didn't do much. Everyone else did the killing. I think I cast a spell or two, but that's about it. And if I hadn't cast the spells, we would have been fine.