I received my Vertax brand 5D MK lll grip distributed by Pixel today. It arrived certified US Mail from Shen Zen China.
Total cost delivered was $90.
The grip looks and feels quite nice. The first thing I noticed was the rubber texture matches the feel of the camera body.
I was concerned about the feel and operation of the joy stick, but it operates well. It has a slightly "softer" feel than the body JS, but seems to work just fine. The buttons including the shutter button work fine during my very limited test.
The one concern I have is the control dial near the vertical shutter button. The movement and "clicks" are softer than the dial on the body and I can see it being a problem getting bumped when shooting or carrying the camera in the horizontal position. My guess is the Canon grip will have a dial with a little stiffer feel but bumping it could also be a common problem. I may likely tape over the dial and could see my self doing it with the $350 Canon grip too.
Instructions that came with the camera are fine. I like that the grip is probably lighter than the Canon grip but I haven't seen the official model yet.
The small markings near the AF and other buttons are painted on and may wear off in time. Just a guess.
Overall after having the grip for a short time I'd say it's quite nice and a heck of a good deal. I'm glad I bought it and likely will get a second one for my other body.