I only use Arkansas Stones. Mainly because they give the smoothest finish and cut slower than any other stones. I take my time and never want to have an "ooopps" by taking too much off. To smooth out an action "properly" takes some skill to do just enough as to not shorten the life of the gun or make it dangerous.

Unless it's being done professionally where time is money and a pro knows when to stop, action jobs are not to be rushed.

Just my opinion and YMMV.