While I can't answer your question directly as I've still got a Meike grip on my 5D3 I can give you a bit of insight on genuine Canon grips. The Meike grip has worked flawlessly with my 5D3 and has been used quite a few times on a tripod with a Sigma 24-70 f2.8 HSM and a Canon 24-105 f4L with no hint of any problems.
I got a 70D body recently and was looking for a grip for it, but as it was so new there was no 3rd party grips available, so the wife ordered a Canon grip for my birthday present. It fits perfectly onto the body and works perfectly but TBH if there had been a Meike version out when I got one I would of got that instead. The build quality of the Canon is fantastic, and I got mine for around £160, but TBH I don't think I could say it was worth 4 times as much as a 3rd party one. I know other people who swear by Canon grips but I've had 7 bodies that have had Meike grips and have never had a problem with any of them. I got a Pixel grip for my 5D3 when it was first available but that suffered from the battery drain problem so I replaced it with a Meike.