I very much enjoyed my short visit to Vino Volo (at the B Gates) while waiting for an overnight flight. I opted for one of the wine tasting flights and a small plate of cured meats. Both were lovely, and I appreciated the presentation of the wine flight. The three glasses came on a little mat that gave you information about each wine.
The staff were very attentive and friendly. I was asked for ID (I am in my 20s) and it was appropriately handled, so I didn't feel like I shouldn't be there.
If I am flying from Dulles again I will definitely be back.