Unlike the old style bikes of the 40s and ealier (now called "cruisers"), these bikes don't even allow coasting with the pedals out of gear.
I like the idea (hate futzing with gears) but am not in good enough shape to get up some slopes in metro Atlanta (eg. the back side of the road around Stone Mountain) without low gears.
And, I need good brakes, as I build up pretty high speeds with the assistance of gravity, then need to stop at intersections (which is why I love the disc brakes on my new urban bike).
BTW, the pros heading up Brasstown Bald (highest pt in Georgia - 4784 ft above MSL) this weekend were going all of 7 mph (slow jogging speed) on the steeper slopes, even with their lightweight bikes and wide range of gearing.