I have the OEM on my 5DIV. It's definitely built solid and I'm happy with it for the most part. The only thing that really bothers me is the button placement. When I shoot in portrait I usually have to pull the camera away from my face and look at the grip to find the joystick button because I have a hard time finding it with my thumb for some reason. Every third party I have owned for my other cameras has done weird things with cutting off use of my shutter speed dial to where I have to turn the grip on, turn it's dial off, then turn it off for the dial on my body to work. Even so, the saved price compared to a minor inconvenience seems to be worth it.