I've stayed at the Sheraton Reston a couple of times in the last month. On the first stay I was upgraded to Club Level on the 6th floor. Unfortunately, the Club Lounge is not open on Friday nights and weekends. There were two complimentary bottles of water in the room. The room itself was tired, but not awful.
On the second stay, I was not upgraded. I was given a refurbished room on the 3rd floor which was much nicer than the first room. I will definitely ask for a refurbished room in the future. The room was a designated SPG room and had one complimentary bottle of water.
One note about the $79 prepaid rate -- even though it was booked through SPG.com, it shows on the bill summary as under the third party internet booking column, and no Starpoints were credited. I pointed this out when I checked out, and they apologized and corrected the error and gave me an extra 500 points.
They seem to have problems with the card keys. I had problems with bad card keys both times, and I noticed several other guests returning to the front desk for new card keys.
For the area, the $79 prepaid rate is a bargain and I would not hesitate to stay here on that rate. What's really nice is that it's usually available starting on Thursday night and through the rest of the weekend, whereas other properties don't start their weekend rates until Friday night. There is also an $89 rate that allows cancellation.