Derwent Super Point helical sharpener from Amazon (delivered today, having Prime is dangerous at times). I was looking for a sharpener that could put a long point on coloured pencil and was, in fact, designed to be used with them as well as graphite. I'm not entirely sure where I came across the info on this one, but it was mentioned/reviewed briefly on Youtube by one of the folks I like to watch regularly and so I put it on my wish list pending a future decision.
So, after getting back from vacation, I pulled the trigger on the device. Setup is easy, it comes with a desk clamp assembly, so you just find a convenient place on your working surface and bolt it on.
To use it, you extend out the front face, lock in place, squeeze the tabs at the top and insert the pencil. Sharpen as much as desired, the face will slowly move in, which ultimately prevents total over sharpen. Pencil waste didn't seem too bad, tried out on a few different options, including graphite and the wax-based Prismacolors, and while it is going to be a bit more than hand sharpening, it's minimal given the size of the point.
You also definitely get a long, very sharp, point! Have look at the brown with a reference "presharpened" yellow from my smaller Prismacolor set. That point on the brown took a few seconds to do and I took that photo after I did a little doodling with it to see how the point held up.
Anyways, looking forward to using this. A lot of folks say you can't put a long, sharp, point on a Prismacolor to get fine detail, but so far it looks like that may not be the case with this sharpener.