I got Vortek sliders from kneedraggers.com
If laid down hard the bolt will snap. I think if I were to buy them again I would try and get the RG.
Its sort of a double edge sword. If you get the cutless then you run the risk of having them snap the fairing where they bolt (but can be fixed with plastex and new bolt). If you get the Rg you run the risk of bending the bolt and maybe even stripping the engine mount.
I read where a kid had both on during a crash. The cutless snapped and the RG bent and stripped the threads where you mount the slider.
The way I see it if you crash at high speeds I think the last thing I'm worried about is the fairings. They basically are good for low speed slides and tip overs.