I'm -8.5 and tried the Rudy Project Horus, but the distortion at the edges of the lenses was too much for me. So I figured I had no choice but to go with the inserts. I went with the Rudy Project Exception because they have an insert designed for high prescriptions. I got them just before New Years - I've been pretty happy with them so far.
One question for those of you who have RX sunglasses. My lenses were cut so that I see 20/20 when I'm standing up straight and looking forward. But when I'm on the road bike, I'm really looking out of the top half of my glasses most of the time, so I'm getting a little distortion in the normal field of view (just like with my regular glasses). Has anyone had their optician cut the lenses to compensate for this effect?