Ok, as a side note, one of the main benefits I notice from riding with clipless pedals is the really stiff sole that comes with the mountain bike shoes I use in conjunction with them. Stiff shoes are waaay more comfortable to ride in for me, and they at least seem noticeably more efficient. If I ride for more than 10 miles or so in soft soled shoes my feet start to hurt.

Off the bike I find stiff shoes really uncomfortable, I prefer something like a pair of vans. So ignoring the benefits or being stuck to the pedal, I would still want different types of shoes for riding and walking. If I'm going to use a stiff shoe for riding only, it may as well be for clipless pedals. That being said I really like being clipped in when I ride.