I've gone the genuine battery grip on the 7D and the Vello grip on the 5D and they both work equally well. The Vello grip is great on the 5D if you are shooting an event, for me, most of the time I'm shooting landscape or snap shots around the yard with the dogs and I don't have the grip attached. But if you shoot a wedding it is critical. And for me the non-genuine Vello grip from B&H is reliable and affordable and I can't tell the difference with the genuine Canon grip.