I have one (i think lol) the one that is like a pipe cutter with a serrated blade?
anyway

have used it a couple of times on very small SWA and found it ok I like the fact that you can keep the cable still and ring it without pulling it towards me to get a hacksaw behind (under a very tight control panel) as you know this ends up with a very uneven length of sheathing
hope that kinda makes sense

I was given mine by a really nice guy I did my 17th with, I always thought there was a market for something like it and he happened to have one in his van and he very kindly gave it to me

(its not very often anything like that happens!!)