I am an NC30 in MAC foundations usually and although i bought the NC30 and used all of it(well not all of it because it went very greasy in the end and i had to B2M it), repurchased the NC25(which wasn't available until recently) and it provides a great luminous result under my eyes.I have heavy dark circles and usually i have to apply corrector (which in my case is the Giorgio armani master corrector) before the MAC Prolongwear to get the perfect result.
I set it with Laura Mercier loose powder which is a bit yellowish and this makes the area uner the eye even more luminous and prevents the product from setting into my fine lines (which i always had).My foundation regimen is as follows: i put on a primer face/eyes, apply foundation or BB cream with a flat kabuki brush,put my corrector under the eyes and let it set for a while, i put powder wherever needed usually in my T zone,apply bronzer/blush, do my eyebrows,then apply the MAC Prolongwear concealer and set it with my LM powder and then go ahead with my eye makeup.In the end if there is fallout i clean it nd apply the MAC Prep n Prime luminizer in pen form under my eyes going out and upwards towards the temples.
My opinion overall on the product is that i provides a full coverage,creamy finish, matte when it dries result that i haven't found in many concealers until now.
Of course as in many things in life, it has a downfall which in this case it is the packaging.The pump bottle makes it impossible for you to control the amount of product you pump out everytime and this results in wasting a lot of product and messing the bottle with the excess product that came out.
I would highly recommend the product for all skin types, i myself am oily under my eyes, but if you have dry skin you could firstly deeply moisturize before using it or maybe get away without setting it with powder on top.