Yeah, I have to agree with wavehog; I tend not to overuse my skeg, but when you need it, you need it and it doesn't noticably slow the boat. As I said before, I prefer the deployable skeg over a rudder, but I wouldn't totally rule out a ruddered boat.
I do think some further refining of the skeg slot should be done to reduce drag to an absolute minimum. I haven't had the chance to try a boat with the high aspect (verticle) skeg, but that might be as slick as a skeg can get in regard to minimizing the slot. However, if it isn't as effective as the more common skeg, then it may not be worth it.