I buy based on different factors. For a BUG, concealability gets disproportionate weight. For a concealed primary, concealabilty matters, but shootability gets more weight. For either, reliability is trump.
BUT, all else being equal, more capacity is never a bad thing.
I do get tired of the guys who say "if you need more than x, you need to learn to shoot."
I consistently shoot perfect scores on pre-deployment handgun quals; I usually score first or second in accuracy at my IDPA club. Does that mean I can't miss if the shooting goes both ways, or if both the target and I are dodging?