I've got one of those and there are a couple of issues you might want to consider:
A: The battery compartment does supply power to the camera but in my case the camera locked up 3x and I could only turn it off by disconnecting the grip from the camera. This seemed to occur when the grip ran out of power and it didn't switch over to the camera's internal power supply. I now only use my camera's battery compartment. Seems like QC is the main iussue with these units if you can get past the missing features listed below.
B: The locking latch on the ION battery holder just hangs out of it's recess and flops around.. won't stay put.
C: The ON/OFF/DOF button is rather flimsy and could break at any time based on it's 'wobblyness'.. lol
D: There is no weather sealing and there are no shock absorbers on the upper surface of the unit. Work out your own implications for that depending on usage I suppose.
E: I paid US$54 from DealExtreme and that included shipping to Australia. That appears to be the usual price.
I'll buy a genuine grip from B&H next time.
Last edited by bossa; 09-22-2011 at 08:10 PM.