In my experience, the more paid-off cards, the better for scores. And PIF'ing the low-limit cards is the simplest way to do this. There's a combination of fewer than half of cards with balances + less than half of all TL's (including mortgages, loans, etc) with balances. Since every installment account by definition has a balance, that means really having to go after the cards.
Congrats on the snowballing! I understand the reasoning behind the other methods, but snowballing is great for morale. Once you fight your way through all this, you'll find that life is a lot simpler with everything PIF'd except for one or two high-limit cards. You can keep a balance of 9% or less on them without a lot of hassle.
* Credit is a wonderful servant, but a terrible master. * Who's the boss --you or your credit?
FICO's: EQ 781 - TU 793 - EX 779 (from PSECU) - Done credit hunting; having fun with credit gardening. - EQ 590 on 5/14/2007