The Viper 12 attains better than anything else I have tested. It ferries extremely well. It catches eddies one would think are too small, and delivers you into them crisply. It can be driven from the rear without throwing you, but it also responds well to being driven from the front.
The standard Mohawk single-strap outfitting is comfy, and easily adjustable. There is a lot of room for all the stuff your kayaking buddies want you to carry. Its volume allows you to blow through a lot of holes that would stop smaller boats. Although now considered old school, this is a hot boat, and I have enjoyed paddling it.
Because of its hard chine (edge) the Viper had the rep of being unstable, but I think it is a very stable boat (flat bottomed). You quickly learn where the edge is. If you lean past that point be ready to brace, but when you lean the boat over it places that edge in the water making a "keel" that will precisely hold your line, and allow you to carve to your hearts content. Where a round bottomed boat will tend to slide out on moves and ferries, the Viper will grab the water.
With the flared outwales, especially in the bow, the boat is very dry in the hands of a skilled paddler. It is possible to control your course with subtle weight shift's and leans. IMO it is a fast boat, especially my glass one. It is an excellent surfing machine as well. I can't recommend them highly enough.