I live near downtown Leesburg.
Anything further in than Tysons will be a problem. Arlington might get better if you can take bus + Metro, and MARC from Point of Rocks to the 270 corridor is a possibility if you're in Leesburg. I'll be honest, I'd rather drive to Columbia from Leesburg every day than drive to DC every day.
Remember, a higher percentage of Loudouners are working in Loudoun today than in 2000. I'm not sure if that's getting skewed by wives/older kids working as teachers, doctor secretaries, retail, etc., though.
Cost of living:
Loudoun taxes: $1.205/$100
P/I on the $540k mortgage @ 4.125% $2,617.11
Taxes on a $600k Loudoun place run you $7,230 p/a ($602.50/mo)
Assume insurance of $100
Total $3,319.61
That $600k place in Loudoun runs you anywhere from $700k to $1MM in Fairfax.
Fairfax taxes: $1.085/$100
P/I on the $630k mortgage @ 4.125% $3,053.29
Taxes on a $700k Fairfax place run you $7,595 p/a ($632.92/mo)
Assume insurance of $100
Total $3,786.21
The Greenway/Toll Road combo runs you $11 a day or $220 a month in terms of workweek. Even with the Toll Road you're still running lower in Loudoun. It depends on what value you place on commuting.
Some services are cheaper out here, other things there's not much of a difference.
PP who mentioned the lack of wealth disparity is correct. There are overcrowded schools here, but it's not like they're pristine and undercrowded in (say) Arlington?
Style of living:
Leesburg, Middleburg, and Purcellville all have functional downtown areas (and in Leesburg and Purcellville) decently walkable strip mall areas. There's (in all three towns) 50s-80s vintage development around the downtown that is cheaper than the new stuff going up in much of the county.
You've got two types of subdivisions: one is the typical 70s/80s/90s subdivision, with a strip mall in the middle, maybe some office buildings, and then four lane roads separating that from where people actually live.
The other includes New Urbanist inspired ideas -- Brambleton, the Village at Leesburg, and One Loudoun are the most prominent of those.
You've also got scads of pre-1950 rural houses in the western part of the county.
Long story short, there are housing options in Loudoun County. If you're in a generic strip mall subdivision, you didn't look hard enough, or you really wanted that new house.
As an aside, Loudoun is less white than Upper Ward 3, Bethesda, North Arlington, etc.
Finally -- 8:02, I think with the militia, it'd cost you $700 a month. But be sure to keep them well supplied in khat, or they might get cranky.