There is a proFab review that is up to 4 pages now. That is a nice looking upper especially for the price (with a rail). I didn't like the dpms slick side uppers, I bought the Lite Hunter, still has the dust cover, free float and 2 stage trigger. The weak spot is the aluminum gas block which can be replaced...
Profab says it is compatible with Palmetto. There are cosmetic lines that don't match up between, your dpms lower has a thick line around the top surface of the lower which corresponds to the upper. Palmetto lacks this, so there is overhang. I'd imagine the profab is the same.
Might be better off finding a dpms upper stripped or cheap and rebuilding it to what you want (new barrel and free float). Be aware of Extra high, high and low rail heights with DPMS uppers.