My question is, how specialized for groomers and carving is the C2 version, compared to the looser (as I recall) RP (Resort Powder) version? Is the RP version in those narrower widths just clearly more for off piste, trees and bumps, or not?
I have the A87 in my quiver, it has the C2 shape and I used to ride a F95, but unloaded it as I didn't like the Foundation construction as much as the Alchemist.
So, the big changes you'll feel with the C2 shaping is the 19m radius, rather than 15 in the RP and the much longer effective edge. Unless you roll an RP ski way over, you really only have around 60% of the ski length edge in contact with the snow. Now, if you do roll it over, an RP can lay down a nice carve, but it's not as intuitive or easy. The C2 will feel far more directional and wants to head for the fall line. The RP is much happier turning all over the place.
In exchange, the RP will slash, pivot, float, and turn far better and faster than the C2 in the woods. I can ski my A87 in the trees just fine, but my Wailer 112 makes me feel like a dang tree skiing god. There is no line too tight for those things. My favorite terrain for the A87, on the other hand, is spring corn and soft bumps. It is fantastic there. I also found it far less twitchy than the RP shape at speed or carving. A high speed GS turn on the Wailer 112 is an exciting experience and I'll leave it at that.
As for getting knocked around in the crud, that is a function of weight more than anything else, in my opinon. You already own my favorite crud destroyer in the Hotshot. I ski the Metal and it is my go to stick for chopped up days. The DPS will slice through fine, if you drive it, and the carbon damping will be there for you. But there's no substitute for 'eavy metal when you just want to tell that clump of snow to piss off and get out of your way. I've had similar experiences with the Renoun Endurance 98. Plenty stiff and strong when I want to drive through tracked up stuff, but it still weighs less than a soda can and you can tell when it gets manky.
I think your decision comes down to where you want to bias your gear. If you prefer stable, damp, and predictable at speed, go with the FF or the Faction CT 1.0 GregK suggested. There's no substitute for metal if you want to bust through stuff. If you'd rather have a more responsive, nimble, "dance-y" sort of feel, get the RP. You'll lose something in cruddy conditions and icy bumps, but you will have an ultra-responsive date in snowy trees. Finally, if you're trying to have a foot in both worlds, like a more "flickable" lighter weight ski, and see yourself not really needing much flotation in the trees, the C2 in a narrower waist is not a bad idea.