I use Studiofinish as my everyday concealer. It gives such great, full coverage without looking fake or cakey. This BANISHES acne scars, hyperpigmentation, dark circles, and other imperfections. I find that this is particularly long wearing, as long as you set it with a powder. I recommend using a transcluscent powder, since the concealer is already full coverage, but whatever floats your boat. ^_^ This concealer applies effortlessly with any brush, but 100% prefer to use my fingers. Also, PLEASE be careful if you have aged skin, as this concealer may settle into fine lines underneath your eyes.
Use as high coverage concealer on blemishes? U can do that. Apply it as a base? U can do that. Use it as an eyelid primer? U can do that.
Covers flawlessly, doesn't look cakey AT ALL, looks like you're wearing NO makeup (which is great). Lasts for a lifetime. I'd buy it again (although I don't think it will be necessary, as I've been using it for over a month and it is still really full).
I wear shade NW25, not NW20. This concealer is amazing for under the eyes as well as for highlighting on the inner part of the face, if you are going to be on camera or taking pictures. This concealer covers dark circles, blemishes and sun spots and stays in place beautifully. I give it a 10 out of 10 if you like full coverage.
I have tried soooo many concealers and by far MAC Studio Finish is the best. I have such darkness under my eyes (since I'm middle eastern) and I feel like this concealer does the job to cover up darkness or any problem areas on the face. I love how it has SPF in it. The reason why I did not give it 5 stars is because it creases throughout the day even when I apply a setting powder on top of it. If I am out for long hours I would take it with me just to retouch up. The powder I set it my concealer with is the Ben Nye Banana Powder and it looks better.