I have only ever used the Dynabrade other than this, and I must say it
was really a night and day difference. I'm a huge fan of HF, but I
think this is one of those tools that I'm going to have to bite the
bullet on and get the expensive version.

They aren't a dynafile, but it's one cheapo that's been pretty good for
me. I use mine more than a lot of the stuff in my shop. BUT I needed to
make a bushing to get mine to 'bite' well onto the (also elcheapo)
angle grinder I use with mine. IIRC it's a piece of 1.25" or 1.5" pipe
with a slit out of it, can't remember if I had it in the lathe to do
more than face it straight or if I did more... Nice and solid now,
however. IF I was relying on one to make money, I'd have an air-powered
'real one' as they are smaller and handier, along with the large
compressor needed.