The shoulder portion of the sling strap is composed of a good thickness (about 1cm in depth) of neoprene. This cushions and distributes the weight of the camera over the shoulder. There is some elasticity to it so there is natural 'suspension' (can't think of a better term) and the camera (in my case a 5Div ... with up to a mid-weight lens such as a 70-300mm L) is very comfortable to wear. I think the elasticity is about right ... you don't want the camera bouncing around too much. The sling arrangement means that you can raise the camera from hip to eye level very quickly.
One drawback is that the lens can knock against the ground when you crouch down ... particularly with a long lens. But you are going to get this with any of the sling type straps, I think. You have to remember to get a hand to the lens first to stop this happening. For street photography, I don't think it's going to be an issue. It can also help to keep a hand lightly on the camera/lens when you are walking around to stop it from swinging about too much.
As I mentioned, I think the simplicity and plainness of the OpTech design would be a plus factor for you. It doesn't scream 'look at me'.
Comment and (constructive) criticism always welcome.