I have one and find that I can keep case length to +/- .003. If your trimming a lot of cases this is the least expensive way to go,but get the power adapter it speeds up things immensely. I'm not shooting for minimum group size just loading ammo for blasting purposes. Oh and the cutter is tool steel was hoping it was carbide.
I have a possum hollow trimmer that I use in the reloading class (alongside a few other ways to trim)... It's gotten a lot of use.
Here's the issue from what I have seen:
The shoulder insert is made from carbon fiber. When and if you get some brass shavings in the shoulder area of the carbon fiber, it will ream that insert, causing the necks to come out wrong if you don't check, and re-do the set screw.
The possum hollow only trims to length, and you still have to do the deburring manually (ID and OD)....
The possum hollow is faster than most of the other ways to trim (RCBS hand crank, Lee trimmer, etc.)