Hi Dianne,
I haven't used that one...yet. Do you have a quilt to UN-stitch? I recently had to take out LA quilting on a 50x50 quilt that had a fold in the backing. I tried multiple methods and settled on the scalpel cutter. It allows you to get close and hook the stitches to break them along the quilting line.
Get between the batting and backing so the quilt front is saved. The backing was toast when I finished and replaced.
There may be other threads here about the trimmers but here is a recent one.
Frogging