The 5d has no business in the air IMO. It's a name people associate with being professional. You spend more, you have WAY more weight, it's still H.264, the large sensor does nothing for aerial video other than maybe make it harder to focus with a fast lens, no 1080/60p, etc. Get a Gh3 or Sony A7 if you want a great all around camera. The BMPC seems to be a great camera as well but keep in mind its a heavier workflow for the RAW most people want it for and a serious crop factor so hopefully you have some really wide glass. I guarantee you no one will know the difference. I personally find it very annoying when a DP asks if I can fly a 5d when I know they are asking me without understanding why it is a completely unnecessary aerial camera. The person who flies a 5D is the same guy who says "I need a cinestar to fly an Epic and a 5D by next week and I've never flown but I just bought a Ladybird..... why did it crash?"
I think you are better going as small as possible unless you actually have paying clients that are using your footage for the big screen or other 4k needs. RAW is nice for the dynamic range no doubt but I still think it's hard to beat some of the smaller cameras out there. One thing I really like about the GH3 and the BMPC is that they have a non-H.264 option. I'm curious how well the pocket camera does with faster motion. The Black magic production cam has global shutter and that will do substantially better when put into post stab at 30fps compared to the BMCC and the BMPC.