Mahalo everyone. A Tevanui is on the way for my friend, Rob. Let the games begin!

It's kind of like the difference between riding a bike with training wheels and without. You're still paddling, but every stroke is a steering stroke as well as a propulsion stroke. You have to understand how the wind, waves, currents, etc., will affect your va'a, anticipate the response your va'a will have to the stroke you are about to take, and adjust your stroke to compensate for all of the above, before you put your blade into the water. I totally suck at it and I still have a blast! It certainly makes flat water paddling fun again.
I can't really comment on boat design, length, construction, etc. as I have only paddled one rudderless, the Tevanui by Tiger. That boat is 25' long (so longer than the typical OC-1), it's narrower than a typical OC-1, and has a sit-in cockpit rather than a sit-on design. My Tevanui is carbon fiber, just like my Hurricane, although the Tevanui is a good bit heavier overall. As for speed, I'm WAY slower in the V1 ('cause I suck), but guys who are good are faster in the flats due to the lack of rudder drag. Due to the longer length, it picks up every little bump, which can be good, although I have no idea how guys surf these things. It's really "loose" on bumps and I wash out all over the place. I have a handicap though in that I have never steered a six-man, so my learning curve is steep and long. Guys who steer tend to pick it up faster (at least that's been my experience).