Pros I've found are the it helps wick away sweat better than a T. The tight fit is nice for not having any loose material blow around. Pockets are great for whatever you need to keep at hand. I've now done away with a saddle bag entirely. Major plus tho is you can unzip the front for added ventilation. (HUGE WIN)

Cons- Cost, tho you really do get what you pay for. (up to a point)