Heading to windward seem to be the best for my D boat.
To a point, the stronger the breeze, the better the boat holds her course.
Feels great too! Ya look over the the high side and it feels like your sitting ten feet off the water......... you can usually see the daggerboard down there, doing it's job....... a little spray in the face now and then. Now this is living
It works dead down too, if I remember to pull up the daggerboard. This is with sails set wing on wing, so steering with sail set is a little different. Mainly just balancing the sails to keep the boat straight down. This doesn't, so much keep you on course, per say, the boat is just being pulled by the way the wind is blowing and will follow the wind direction, even if the tiller is locked down (As long as the daggerboard is all up). Very quiet and relaxing, if that's the way you happen to want to go
It can sure get hot in the cockpit in warmer weather though. SK
& 
have a break on the steering?
