Last Summer, BoB went with a radial cut dacron from North. We ended up having it mounted on slides so we can use it for racing and casual sailing. Pretty happy with it as it starts and stays much flatter than the old panel-cut dacrons and with our 3DL headsail, can pretty much out-point our competition. Put the money saved into a new spinnaker.
Our North Sails combo of 3DL headsail, radial cut main and new spinnaker got us a third in Round Whidbey race last weekend. A 72 rater and a J-80 beat us. Getting ready for the Northern Century double handed and I won't be following Slingshot....