I will answer my own question by saying I visited Arlington and was not impressed with GMU. In addition to flubbing my appointment time and date, the admission staff assigned the office manager, who was hard to understand and basically read a quick facts card to me and the other family. The office promotional literature was out-of-date and read "Fall 2007." The marketing was terrible. I had to tell myself what Mason's strengths are, because the staff didn't make it clear why I should go there.
Also, the school is situated on the fairly busy Fairfax Dr. in Arlington but there is no campus feel whatsoever. Moreover the $38k tuition for out-of-state students comes across as a shameless money-maker while in-state students get the $18k tuition. The "buildings" -- because it's not a campus -- feels small and not at all like a community. Academically I could pursue the exact same program elsewhere and thus have no remaining reason to attend.