repti bark is hard for new keepers to use i would say. its dark in color and can hide mites and other unwanted things easier. it has a lot of dust as stated.
aspen doesnt hold humidity at all, doesnt matter for corns really, but some animals it does. if it needs to be humid in that cage it gets moldy faster than other beddings.
cypress mulch is a good alternative, looks decent, holds humidity but also dries out like reptibark does after time.
coconut fiber is good for aboreal species and holds humidity pretty good and i think it looks awesome.
a lot of people use a mix of things such as sand, dirt/peat or whatever it is and moss. i havent done and it and have no experience of it but you could look it up.
i use aspen for all my animals in their normal homes, but in quarantine they get paper towels or newspaper just laid down.