"William R. Watt" wrote...
true double ended (pointed, not flat ends) don't sail well upwind.
when they heel over the curvature of the side of the hull develops
terrific weather helm. you have to pull the tiller up under your chin
creating a lot of rudder drag until they finally luff up and stop.

Hmmm... Sounds like someone who either has not sailed a double-ender, or only
sailed a badly-rigged one.

Mine (SeaPearl 21) sails upwind just fine, and can be easily and repeatably
trimmed hands off the tiller with a centered rudder and no luffing sails.