I just use rats, period. but I understand, smoe people need to use mice because of the scarce availability of smaller rats at most pet stores; many places won't even sell you any rat that isn't weaned yet.
From my smallest '06 girl (the once from Cue) all the way up to my BCI, all of my snakes are on rats; though, the first 2 feedings of my Pastel (who is still acclimating, hasn't been fed by me yet) were admittedly mice, and ginger used to eat mice. I like the rats because I rbeed them myself, and also they don't smell as bad as mice!