I have just had mine delivered today at £150 for 4 15inch 2118'S in gloss black powder coated.
I'm Senior BMW panel technician in an approved BMW bodyshop. If powder coating is good enough for BMW wheels then its good enough for me.
The company we use is in Scarborough called Rader. They have bought a fancy machine that the wheels go around automated through acid dipping, blasting, cleaning, priming, baking, colourcoat, baking and out completed in 1 hour. They come out with a perfect finish, no dry spots no runs no bits of s**t In them.
Only thing to look out for it coatings on the mating surfaces with the brake disk. If they are not clean they act as in insulator and the heat cannot disperse from the brakes through the alloys and it's been known to warp disks.
I would choose powder over paint every time, plus it's better for the green peace guys lol