Track bike geometry is implemented for maximum power, with little thought given to comfort. When riding on the street, there are benefits and disadvantages to track bikes, all relative to riding a converted road bike:

Pro
Agile, quick steering
Tall bottom bracket offers excellent pedal strike clearance

Con
Harsh ride
Unstable handling at low speed
Very limited clearance for larger tires/fenders
Steep seat tube angle makes proper bike fit problematic for distance riding

Fortunately, most fixed gear bikes that you'll buy in bike shops and from internet dealers have evolved from strict track geometry to a style that's more a hybrid of road and track. You still get the tall bottom bracket, but you also get slack headtube and seat tube angles, as well as wider tire clearance.