Join Date: Jul 2007
Location: Salt Lake City, UT
Bikes: Co-Motion Speedster, Giant FCR2, Surly LHT, Surly Crosscheck
Malkin and I started on a Diamondback. It was a great bike for casual rides--very comfortable (upright positions front and back) and easy to maintain. We moved up to a Burley and then to a Co-Mo when we wanted to spin more miles and became strictly road riders. I'm 6'2" and found the frame to be plenty big for me. The only real answer to the size question, though, is for you to some fitting work on the bike.
Best of luck and lots of fun!
2008 Red Co-Motion Speedster Co-pilot (Redster)
2009 Surly LHT (captain's commuter)
2009 Surly Crosscheck (stoker's road bike)
2007 Giant FCR2W (stoker's commuter)
1980's NOS Legnano (stoker's toy)
1970's Stella rebuilt as fixed-gear (captain's toy)