Probably the biggest reason I was considering the 1Dx was the integrated grip with the second MC. I really liked my 1DsII and the only thing missing to me was a MC and thought of having one for vertical too made me all fuzzy inside. But now with the BG-E11 I don't think I compromised too much with the mkIII. I just try not to think about having $4k (I paid tax on the body) invested in a body/grip too much.