On-time payments are something like 30% of your score. Holding a balance is not a positive factor, though, and having a balance that is a large part of your available credit is a negative. You will get the same benefit from on-time payments if you pay the cards off as soon as you can and then use them for routine monthly purchases (groceries, gas) and pay the balance in full every month. That way you get the benefit of on-time payments without carrying a balance. As long as you really can pay the balance in full and don't get behind by over-spending.
