I just brought home a lovely Trek 520 a couple of weeks ago. I test rode one (it was sold, so I couldn't ride far) with the original saddle. I told them not to bother to put the saddle on my bike. OUCH! I have a butterfly on it now = happy butt.

And...it's a sweet bike! It was a perfect fit for me according to the fit kit I had done with zero changes in stem, etc. Down to the 1/2 cm. Sweet!