There was only a single mention of the word knees in this entire thread. And while I understand that with proper technique you can probably ride safely without injury to your knees.

To me this is unneccsary wear on the meniscus, why put the extra strain on it. A fluid stop without a brake can be achieved, but at what cost, is all the additional grinding neccessary. I love my fixed gear, its a great ride and i enjoy the benefits, but i am not so sure i want to add to potentially cripling list of geriatric ailments.