Agree with everybody: do a bit longer ride 'cause it's your butt that counts... but in two weeks you'll probably like the 7300 better.
My friend was toying between the 7100 and 7300 until I got her to get on the 7500 (which fortuantely was on sale and so not *that* much more expensive). Even in the dead of winter she's been out just about everyday.

SueJ, webmastress
http://www.resourceroom.net