Don't forget that BWI stands for Baltimore-WASHINGTON international.
D.C. is a great area with lots going for it and a bunch of great suburbs (of which Calvert County is one). Home prices are absolutely outrageous, though. A decent neighborhood (with 20-40 yr old homes and 1/4 acre lots) will run $500-$600K plus. Anything new in the adjacent suburbs (Montgomery MD, Fairfax-Arlington-Alexandria VA) is over a million. It can be very depressing for a potential home buyer looking for what they grew up in. In fact, without a lot of equity from another home or another good income, D.C. in the last year has outpaced a new FO's ability to move here (unless you don't mind renting). The suburbs out West (rte 66) and south (rte 95) provide more for the money (though still pricey) but I wouldn't wish that commute on anyone. It's 60-70 minutes from the heart of Fairfax Co. to the parking lot, about the same as the southern PA ride.
If you can overcome the cost of housing, I would highly recommend the D.C. area for culture, jobs, growth, activities, etc.
Good luck with the search.