I ran a big Hooter on the SC20 (28' luff) last year, and installed a spin/snuffer set up on it this year. The Hooter worked well from a little above a beam reach to maybe 40 degrees below the beam reach. The spin runs substantially deeper. The Hooter requires real self discipline, it needs to be furled at around 12kts, over that it becomes problematic to get it furled. I also had it set up so that I could drop it to the tramp (releasing the tack as well) if problems occurred, or the wind picked up over 15 kts. Then I didn't want the additional windage. I also rigged the Hooter halyard w/ a 2 to 1 purchase to get sufficient luff tension. Overall, it worked very well in light air, gave the boat a massive amount of sail area, was easy to use just toolin' around.
The spin/snuffer is almost as easy to use, and does work deeper. If you're mostly reaching around for fun in lighter airs, the Hooter might best serve your needs. If you spend a lot of time going up and down wind, the spin might be a better choice. Also, not choosing the largest possible Hooter might minimize some of the difficulties I occaisionally experienced.

Dave
H16, SC20, custom carbon DC 24