Trek confusion

Question
Hi I would like your advice.
I just purchased a trek 7.3 hyrbrid bike, 17" frame, I  like it a lot, its so comfortable and fast 700-wheels. But my only concern is about the tires, I took it out on the side walk and I can feel every bump, and I am not going to ride it on the road with cars. I plan on using it for some rough urban riding, exercise. The side walks are bumpy where I live, also my college campus.  The lady said it should be okay for campus, but im not sure. I am debating on exchanging it for a trek 4500 model which has bigger wheels and front suspension, and a hard tail frame, I heard the seat sucks, I am afaraid it wont go as fast, but more durable!
I just want something for urban riding, that I can go over bumps and dips and some sand.
 but im not sure about the 7.3 Fx's ability to ride on un smooth sidewalks, and other than bike trails.
I want a light bike thats durable for urban riding and under 600$
what do you think?

Thanks!!!

Answer
Hey there!

Sorry it took me a while to get back, I was on vacation and forgot to set my settings!

Well, you asked the right guy cause I had the same dilemma! A 700cc wheel will go faster than a 26 inch, however, with a 700cc rim you CAN'T do aggressive riding AND you will feel more bumps in the road.

If you want to do aggressive ridding the you need a 26 inch rim. It wont be as fast (maybe a 10 min deduction in time) but you will be able to go off road and take short cuts where as a 700cc rim just can;t go with out destroying the rim.

So its really a matter of what you want, speed or durability. 700cc = speed and feeling bumps in the road, or, a 26 inch rim = durability with 10% speed loss and less road feel.

I know this cause I have the Mavic Crossrides on my bike (26 inch) and I see the 700cc zoom by. But I know if I go off road or take a short cut trail, they cant keep up or follow me : )

Hope this helped you out.