I would absolutely choose AKV Concierge if I could get it! DH & I plan to do just that some day...go for a romantic weekend to AKV-C with NO KIDS! I think concierge would be nice to have if you are going to be hanging around the resort a lot & taking advantage of their offerings. Plus a nice romantic dinner at Jiko sounds perfect!
I am sure you could choose anyone of them because they are all awesome in their own right.From what I have stayed at so far (all except BLT and AK).I really like the Boardwalk with BW view.