I come to Reston two or three times a year & this is the hotel where I choose to stay.
Downside first - there is nothing much in the immediate vicinity & it cannot compete with the Hyatt on location at Reston Town Centre.
All the rest is good, very nice rooms (I was upgraded as a Starwood Platinum) to a junior suite which was very well appointed, laid out & blissfully quiet (despite facing the Dulles road).
The bar is very nice (so much better than the Hyatt) and the food was excellent. Although I didn't use it on this trip the pool & gym are pretty good too.
So, if being right in RTC is of prime importance stay at the Hyatt, if not stay here & use the shuttle to get to RTC.