I have had very good luck with 3rd party grips from 3 different companies for 3 different cameras(D90, 7000, 800) but a few people have had problems such as the battery closure tab is not very strong. Combined, between the 3 cameras however, I have about 120,000 in rough conditions and find the grips accept the abuse possible better than the cameras since they look like new.
A quick search revealed dozens of threads concerned 3rd party grips.
If a 3rd party grip is a goof risk, the answer would probably be best predicted by how rough one is with their other equipment. Do you often break things? I know some people who often complain about weak consumer items and how easy it was to break them. I must be easy on things because there are very few items of any type, from cars to delicate instruments. My ex could break anything, from wine glasses to auto transmissions on almost a daily basis. The Nikon made unit is part metal and party plastic and the 3rd party grips are entirely plastic. Stan St Petersburg Russia