I am building a 7A, but flew with Mike Seager last week in the 9A and the 14A.
Ingress into the 14 is a bit easier with that lower longeron. Seating is definitely more upright and a little more shoulder room than the 14, but I kind of like how you sit a little lower in the 7/9 and had no issues rubbing shoulders with Mike. I also (again very little time in both) like not having the center tunnel in the 7/9. I am 6'4" and had no issue with headroom in the 9A (surprising) if that is an issue for you too.
Can't go wrong with any of them, sit in all, choose your most common mission and enjoy. I guess the nice thing about the 14 that would sway my over the 7 if making the decision now would be advances on the kit.