I've tried several primers including MAC paint pots and UD primer potion. I've found this to be my favorite by far; it goes on smoothly, dries quickly, neutralizes my reddish lids and dries completely crease free. It leaves my lids silky smooth with no crepey texture and looks simple and classy with a touch of liner and mascara for a fresh clean polished look. MAC paint pots are faster in terms of application but they always came off as chalky on me and I never understood the popularity of UD pp.- a messy annoying applicator with a product not easily visible.
I bought this brush when I was looking for a good brush to apply Latisse for my lashes. It's a bit stiff but the perfect size to precisely stroke across the upper lashline. I can't imagine using it for concealer other than tiny areas. For a buck-I'm pleased!