It's a load of BS. Let's see:
Originally Posted by CarlB
His sense is that there is a small increase in efficiency (to help get through the difficult spot between 10:30 AND 1:30 in the stroke)
It's a huge increase in efficiency. It transforms the whole way you pedal by allowing your cadence to go way up and put in almost equal power through the whole revolution. Takes a lot of strain off the muscles by 1) using more muscles 2) using them in a smooth quick movement instead of a slow mash that gives you a cramp and kills your joints.
Originally Posted by CarlB
and being clipped helps keep your foot on the pedal when hitting potholes or when the pedals get wet and slippery.
Yessir. It's better to have your feet on the pedals in 99.9 % of the cases.
Originally Posted by CarlB
he notes how much easier it is when unclipped to get on/get off
If you lack coordination, it is.
Originally Posted by CarlB
how one doesn't have to worry about which shoe you're wearing and,
Only drawback of clipless. Not a big deal with all the pretty nice looking MTB shoes that you can walk around in without much trouble.
Originally Posted by CarlB
you can use more muscles unclipped than when you're clipped in (because you can vary the position of your foot).
That's an immense idiocy. There is only one foot position in which a person has ideal power transfer, and clipless allows your foot to be in that position all the time (provided that you set it up properly in the first place). How would shifting your foot forward or back help anything? If you shift forward, you can't help in with your ankle. If you move your foot back, you overstress your calves.
The problem with the guy is probably that he never learned to use clipless properly. Set the cleats wrong and didn't find the correct foot position, never learned to unclip subconsciously, never learned the correct circular pedaling with a high cadece that would have allowed him to enjoy the benefits of the system.
Of course, not everyone want or needs clipless for the commute, but anyone who wants to ride fast does.
Edit: is this guy the boss of Rivendell that goes on about how every bike has to have the bars above the saddle and puts a ****ing eyelet halfway down the fork for a demented front rack?