As Mark says, I used the Ullman for single handing, as the newer Landy that I bought had a deliberately full cut for 2-up sailing, and I always found the Ullman very quick when 1-up.

I'm afraid my tuning isn't particularly scientific. Upwind: I adjust the mast rotation so that the back of the sail and the back of the mast form a nice smooth curve, and then generally leave it alone. I find that the big one to get right is the downhaul. I generally try to go upwind by making very small steering movements, rather than by playing the mainsheet (more through laziness than any belief that it's quicker). If you find yourself luffing significantly to get the hull down in the gusts, it's time for more downhaul. On a number of occasions I've found more speed by using more download than I thought I needed, footing off a bit and going for boat speed. I spent a lot of time racing the Stealths, and never out pointed them, but often got them on VMG by going lower and faster.

Downwind: again, I do it more on the steering than the sheeting. Cleat the main, quite loosely when light, hard when it's blowing, and then sail to the kite. Don't be afraid to go really high in the light stuff to get some boat speed.

Paul