how about for during an actual race?
Do any of them have a decently accurate 'heading' angle display? - to take the place of a compass for reading wind shifts?
You are not allowed any device that will show you any data during the Race. You are only allowed to use GPS devices that will give you the info after the race. So no devices with Heading Angle displays.
For the original Question:
I use my Iphone 3GS and use the GPX Motion App. I view the results with the gpsarpro Software.