Greg's place is fantastic - just as advertised. It was the perfect home away from home for my family for a Christmas getaway. The kitchen is well appointed and had everything we needed to cook all of our meals. The bathrooms were both recently updated (the larger bathroom downstairs is particularly nice) and had quick- heating water in both shower and sinks. The sitting room is lovely and cozy, with cable tv and lots of board games which definitely came in handy when there was a particularly severe cold snap during our stay which caused us to spend more time inside.
The place is close to a large Giant supermarket, Whole Foods and several nice restaurants a few blocks away on H street. If you don't mind a longer stroll, you can also get to the Union Station/Capitol area within an hour and allows for a nice tour through some nearby D.C. neighbourhoods.
I would definitely recommend Greg's place for a family vacation.