I'm 6'2" and 235lbs (lost about 10lbs in the last few months).
I have managed to crack the chain stays on a Steamroller but Surly replaced the frame quickly and said that there had been a problem with the heat treating which caused the problem (this was about 3 or 4 years ago so I think you're safe). I only mention the problem with the earlier frame to highlight their customer service. They did want me to do the exchange through a local shop but other than that relatively minor inconvenience the service was prompt and courteous.
The newer Surly went through a dooring that landed me in the hospital for a few days with nary but a small (barely perceptible) ding in the downtube. I had it checked by two shops and they said the alignment was just fine. I recently replaced that frame because I wanted a larger bike. But it served me well for 3 or 4 years and has plenty of life left in it.
Surly is a good way to go.