I can't speak for the CGs. But if your coming from NJ fort Meade is much easier to get to. Access to DC is doable from both. Fort Belvoir is a bit closer but as a result it's in a more congested traffic area overall.
19'Duramax w/hips, 2022 Alliance Paradigm 390MP >BD3,r,22" Blackstone
r,RV760 w/BC20,Glow Steps, Enduraplas25,Pedego
BakFlip,RVLock,Prog.50A surge ,Hughes autoformer
Porta Bote 8.0 Nissan, Sailun S637