Actually, the tablet is (in my opinion) the _only_ form factor that goes well with gestures. Desktop and laptop displays are not convenient for touch-based input, and phones are simply too small to easily input complex finger movements (although they work fine with a stylus). If you're going to be moving one or more fingers in lines, circles, triangles, or whatever, the tablet is just about the perfect size and held in the perfect position to accomplish those feats.
I've tried out some old Sailfish OS build on a Nexus 7 and the UI was just fine.