Is you seat height adjusted right. You will find your butt getting more constant pressure from you seat if your seat too low. A properly adjusted seat help relieve some weight off the seat while you are pedaling.

I have yet to buy a bike and not change my seat. Most are bearable but still somewhat not personally fit right. One on my favorite seat on my commuter bike is a Serfas Dual Density Gel. Just a note, what works for me may not not for you. It's more of a trial and error thing.