Looking for an ipad-based mixer. Which is best out of the Mackie DL1608, Behringer XR16, or the PreSonos model?

Depends on how you work. Size wise they are all the same but I prefer Behringer. If you I/O are more essential to you then go with StudioLive with the Behringer finishing up at a close second. However, if ease of use is what you are after Mackie is where it's at. Personal choice is BEHRINGER - If I had to help a friend, I would say Mackie. Hope that makes sense - ha!