One minor caveat. Some card issuers may limit the number of payments one can make in a month, or statement cycle. Wells Fargo is one of them. Limit is 2 payments within a cycle period, if paying on line with their system. A payment can always be pushed through. This is not, however, bad. Simply somewhat inconvenient.
I too keep my cards at or near zero balances. I pay my Wells Fargo credit card several times per month. I have never been informed or warned of any restrictions on how many payments I can make in a month. I know for certain there have been times I paid it more than 4 times in one cycle.