My Pixel grip for the D7000 had to be returned. Due to electrical problems causing the battery to drain. This is just one man's opinion. The delivery time was real slow when ordered off Amazon.com. They were nice about communications, and I got a refund much quicker than the delivery time.
Genuine Nikon grips are built on a framework of magnesium. I feel it to be more solid. When mounted on a tripod with a heavy lens, that is a lot of weight to bear. Yeah, I'm not happy about the price Nikon charges. For just casual use and hand-held with smaller lenses, you probably wouldn't know the difference of any of the brands Stan had such good luck with. And if you only have one camera, the cost isn't astronomical.