My fixed gear bike has been my bike of choice for the better part of the last 5 years. I got it to enhance my training, figuring that every minute I was on the bike, I was pedaling. It's also helped develop a smooth cadence, which has morphed into a smooth, high cadence. With cyclocross tires, it's an outstanding snow bike too. The direct drive translates to much better and more predictable traction. It's also nice not to have all the shifty-bits to maintain.

I have mine set with front and rear rim brakes, as my original hub had the option of flipping to a freewheel. I really didn't want to be freewheeling with only one brake. The reason many set up fixed bikes with only a front wheel is because braking on the front wheel helps slow you in general, but also shifts your weight forward, allowing the rear wheel to have less connection to the ground so you can slow your legs and stop the rear wheel more easily. The brakeless folks use the same concept by throwing their weight over the front wheel while simultaneously locking out their legs to lock up the rear wheel & skid. I like my tires too much to do that.

It's certainly got a lot of fad to it and it's not for all, but I'm still having fun with it