It is very dependant on the purpose of the site:
- Dolphin U - has no mobile app, but Dolphin U based site already looks great on mobile
- Dolphin Pro/Classic/7.2 - has mobile app, but Dolphin Pro based site isn't looking good on mobile, however we will try to make it responsive, but Dolphin U is better on mobile anyway since we adapt it for mobile from the very beginning

Also they offer different set of module - at least for now and in the nearest future:
- Dolphin U - has advanced communication see more module, multiple profiles per account support, advanced blogs system, more social comments/timeline/notifications.
- Dolphin Pro - has a lot of modules for almost every purpose, but in some way they provide limited functionality