All right this pretty much confirms the cabin lengths for me. I still can't find a diagram of the 7X but I do know that Dassault advertises the Falcon 900 cabin length at 32'3" and I was able to find this diagram:
So Gulfstream and Bombardier figure cabin length including the baggage holds and it appears that Dassault does not. Out of all the websites that allow you to make comparisons between aircraft specifications, I've seen them all use the official numbers form the manufacturers without a single one that mentions that comparing those cabin length numbers is apples and oranges. I don't know if Dassault does this because its their tradition or because the regulations don't let you access the baggage at all above 40k... I don't know but it seems kind of stupid of them from a marketing perspective.