In addition to rolling better you will have better gearing without the added weight and mechanical complexity of internal hubs and cross drives. Also, leisure riders may find smaller wheels suitable for long tours. Smaller wheels may be less efficient but that doesn't mean they're unusable. On a recumbent an aerodynamic tuck is achieved by placing your feet up in front of your torso. Many designers feel that bikes with cranksets on about the same plane as the seat put the rider in a more powerful position for climbing.
Some people find the high crankset bikes more difficult to balance as well.
The trick is to match your anatomy to the seat that fits you best. Some seats are made with a hard pan base or a slung material base. Some remove easily and some do not. Seats can recline or position you more upright. Remember that the more upright you sit the more pressure there is on your butt which may cause problems on longer rides.