I noticed you changed your signiture to say "Magnum".
Seriously, though, I love the Hooter. It is easy and really helps out upwind in the light stuff. It really makes a difference on my Hobie 14 and I'm glad I made the change. I'm getting one for my Supercat 20 and I'm working on getting one on a friend's Sc17. I don't think the windage is too much of a problem if you have a tight luff and can furl the sail tightly. I found that in heavy wind, it doesn't always furl nicely, so the upper part of the sail flaps around.
One change I would make to my set-up is to add a block to control the tension of the luff. I cleat it now and it isn't always optimized. Also, you HAVE to have a fairlead on the furler or it just won't work right.