I put 1500 miles (in one year) on a 8 year old Diamondback hybrid and finished off that season with a century (5000ft of climbing). Never had a single problem. Crashed it once and it came through without a blemish. I would say that Diamondback makes a solid bike.
I did buy a Trek Pilot 5.0 after that season because, like you, I wanted a road bike.