I would like to add that I have only uploaded percussive sounds yet, but I assume that any kind of sound would work as long as you are aware of that space is limited. (I don’t remember how many megabytes)
Also, if you are looking for a device to start and control long-length samples and/or loops, the DTX may not be the best device for that. But I cannot make recommendations for that use case, at this point.
Hope this helps!