Regarding the rough ride concern, many recumbent trikes use mesh seats, which absorb a lot of shock. Not quite as well as a good suspension system. The biggest issue is the seat height - too high and it's hard to get a leg over the main tube and easy to tip in corners; while too low and it requires doing deep-knee bends to get into and out of. And if what's available for rent is those cheap 1 or 3 speeds, it won't be worth the effort.