I've done some forest roads and the associated bike dropping with the EVO bag on and never had any issues. I got the Evo for a steal, but I don't think it's the best looking on the bike. The contour of the bottom of the bag doesn't match the slope of the tank, so there is a significant gap about half way back, if that kind of thing offends you. I don't think it would hold a big lens on a SLR either. City or GS may be the way to go.
It works for me just fine though. I carry a point and shoot. And a camera, too!