Jack;341 wroteHi @[deleted], thanks for getting involved.
Are you experiencing any audible glitches/clips when switching? If so then try increasing the buffer size in the "General" settings view.
Also sometimes loops can sound odd when switched exactly on the beat. You can often get better results by turning off "CUE" and switching the groups manually.
EDIT: One more thought, with slower devices it can take a little bit of time to actually switch between groups and this maybe what you are hearing. Actually i'm planning to optimise this in the next update.
Jack, your last comment may actually be on the money as I'm using an iPad 3. Glad to hear you're working on that! Thanks