Have to disagree on that end. The wind pushes the batwing around a bunch more than the frame mounted fairing. With a batwing, it's pushing right on the handlebars. Our SERG was MUCH more stable in Oklahoma winds than ANY of the Ultra's we've had.
The only place a RG might be better is in a crosswind situation. I believe the buffeting on the rider (affecting comfort) is much worse on the RG. As far as 'wind-steer', the bat-wing has a slight disadvantage, but having experienced both fairing on the same bike, I'll take the protection of the batwing over the shark-nose any day! It doesn't make sense to me to have a fairing that makes you more uncomfortable than not having one. Frankly, the Road King I had immediately before the RG was better at protecting the rider and passenger from the wind and elements.
I'll also add a bit about aerodynamics too. I did two iron butt rides on that bike. a 1K with the shark-nose, and a 2K with the batwing. The MPG didn't change, so that tells me the fairings are similar in efficiency.
I will not accept that one or the other is the best. One may be better than the other for a particular rider. I've weighed the pro's and con's in a way that few can, and I don't think there's any confuion about what opinion I came too.