Track bikes are awesome when the roads are really smooth, or for weaving through traffic or other obstacles. However, they are not optimal for long rides. I ride both my track bike and "relaxed" road bike on long rides and the difference is noticable. The steeper angles and shorter wheelbase of the track frame magnify the bumps and the handling is sketchier over road irregularities and as you get tired, especially when something happens, like when fast moving traffic squeezes you into a rough pothole-laden shoulder, or when you hit an unexpected patch of gravel at the bottom of a hill. Those situations suck with a track frame. I've noticed that I also have to concentrate harder when doing things like drinking from my water bottle at speed.
I still like riding my track bike long distances...if I wanted optimal I wouldn't be riding fixed would I? However, when the ride gets up into the 100 mile range, I'd much rather be on a road oriented bike.