One disadvantage of not being cut is that your foreskin can poke out and get trapped between the cage and clothing. It's probably easier to line up and pee through the cage, as it's more awkward to poke your foreskin back if you're uncut. (not possible with some devices). It must also be easier to wash, and stay clean, while caged, less folds of skin to trap dirt. I would have thought that to wear a cage, being cut is simpler and more hygienic, especially with very short cages (where there's less penis but still the same amount of foreskin!), but I can only comment from the uncut side of the fence. Having said that, I would say there's at least as much difference between a plastic and a steel cage for similar reasons, and the configuration of the end of the cage (closed, tube with punched holes, bars, space between bars, ...) again makes at least as much difference with the above factors.