I've just seen a photo of the 7D with its grip over in this thread, https://photography-on-the.net/forum/showthread.php?t=748806
that grip looks massive compared to the 350D grip that i'm looking to upgrade, so I have some concerns.
I tried the 1DsIII (I think the 1DMkIII is the same) at warehouseexpress back in May and I'm not sure if it's just me, but the portrait grip felt smaller than the grip on the 50D did, and much more comfortable to use.
Does anyone have a 1DMkIII and a 50D w/grip who can provide me some comparison thoughts?

