This thread clearly shows that the 1D3 does not lack IQ by any means. I dont know why I still am so reluctant to give up 10MP for this camera. This clearly has the options I want, but not sure why I feel like losing the 10MP is a big deal, when reality tells me its not a big deal.
I don't know, either. While my 5D3 HAS taken over as my primary camera for weddings, I still shoot the 1D3 right alongside it, and when I'm processing them in LR I usually can't tell the difference between them.
I've considered a 5D2 or a 6D, but the 1D3 is so responsive and overall excellent that it makes more sense to keep it. The weather-sealing has come in handy, the relatively fast sync speed matters to me, the battery life, etc. etc.