I don't have any Sorby chisels but I can recommend the regular AI's. I have found the edges crumbled at first but after sharpening to around 35'ish deg or so they hold their edge much better.
I don't recommend the AI butt chisels though. I'm sure the steel is just as good but I find the handle small and uncomfortable unlike for the regular chisels, (but of course each to their own with handles).
cheers,
Ike