I'm with bac, who said not to get hung up on the frame material. Tire size and pressure will make much more difference in feel than the frame material will, at least until you get into custom bikes where the builder might choose tubing specifically for your weight and the way you ride. Buy something that fits and has room for tires up to at least 32mm, and don't worry much what it's made of.
Having said that, though, four of my five bikes are steel: Atlantis, Rambouillet, old Trek converted to singlespeed and an old Bridgestone mountain bike I commute on (my newer MB is a Cannondale). They've all been durable and comfortable, and a couple of them have survived pretty stout crashes. If I were looking for another bike, I'd have to be convinced not to buy steel again.