The hosts were terrifically welcoming. I showed up early (faux pas!) but John couldn't have been nicer about it. And before I left I needed something last-second and they were very fast to accommodate (and they did not have to, so it was very much appreciated).
The place itself is very spacious -- huge bed, big sofa, nice kitchen (though I didn't get to use it). The location was very convenient to the hopping area of Adams-Morgan. A 5-minute walk and you have your choice of bar or restaurant for a good night out. It's about a 10-min walk from Dupont Circle Metro station, and while that was no problem for me, if you have a lot of bags you may want to cab it. Also there is a city bus right around corner to take you to Union Station, so keep that in mind if taking Amtrak or Bolt/Mega into town.
Finally, the code entry was VERY convenient and I loved that option. No key exchange needed, no worry to hang onto key, just super easy.
Good communication overall, a nice place and a hearty recommend for your visit to DC.