I have tried a lot of QD's over my 3x Platinum UPP (Showtime, Platinum, QS, EO and 3M GE.)
The one that I use the most often is the 3M. For me at least, it is a true "gloss enhancer." I use Poorboy's S&W to get the rain crud off the car. Then the 3M.
It probably is my imagination, but the 3M seems to minimize minor defects on the finish. It's not a true glase, but its ingredients (trace amounts of two types of alconol and carnoube wax) does the job for me.
Plus, it's only $25.88 per gallon DELIVERED!