I'm no expert here but have been down the same road so I'll offer my 2 cents FWIW.

First, I feel you pain on the AARP mailings. Nothing makes you feel older and /or warrents purchasing a new "toy" more than your first mailing ;-)

That said, like your first girlfriend, your first bike, won't likely be "the one". Any bike you choose will be a compromise based on your feelings at the time. Your feelings/wants/needs will almost certainly change if you stay with it. FWIW, I started out with a ( $325 schwinn Sierra) 26" wheeled hibrid and initially loved it for it's upright riding position and cushy comfort. However, within a few years, I craved a lighter, faster bike that would be less tireing for longer rides so recently moved on based on good advice recieved here.

http://www.bikeforums.net/showthread.php?t=572025

My personal advice is to reseach here then test ride every style and brand bike you can get your hands on before you settle on a style/model that fits YOUR more educated wants/needs list for the proper ballance of comfort, speed, weight and price. Then if your still not in love with anything, shop the used market so you can save your $ for a more informed decision once you've riden a bit.

Also FWIW, I test rode a 7.3 a few weeks back and thought it was a pretty versitile road/fitness bike. Not sure it would be my choice for crushed stone surfaces though.