As a frequent AirBnB'er, I read prior travelers' comments carefully. I concur with many- neighborhood is gorgeous; parking at night is fine but in day a pain; if you're in Master Room #11 (there are several different rooms in basement) the walking on "ceiling"/floor is VERY loud (remember, this is someone's HOME, and they LIVE THERE full-time!); the bathroom plumbing is old, yellowed, and tub/grout mold-stained; room and bathroom corners dusty; several other rooms in basement can be full and you're sharing bathroom with up to 6+ people & they sometimes leave it messy. 20-25 external STAIRS to the basement are VERY STEEP, difficult to navigate in our pouring rain (would be anywhere, frankly), and the "Warning" signs around inside are VERY unfriendly though true. Hosts have apparently had disrespectful guests who didn't follow rules, so felt it necessary to put up physical warning signs as well as include in their Post. Bummer the disrespectful guests have made it difficult for everyone.
The bed itself was very comfortable & clean, room as pictured, beautiful green view out windows in September, and close to GWU/Mt. Vernon Campus and other sites up in this area.
We did leave after one night (instead of staying 3) and forfieted our payment, 'cause my sister couldn't deal with the negatives above. Since nice Hotel rooms are "less expensive" right now due to Covid, we found something for same "all-in" price of this space. Had to forgo $$ (since we "changed" reservation on-line rather than talking w Dennis first -our mistake), kitchen and great location at the last minute, but for sis, it was worth change and more$$.
If you're OK with the above, and the pricing/value is good for you, I recommend Dennis' place. (He does communicate well; unfortunately, our issues weren't really "fixable" during the stay.)
If not, stay somewhere else so you're not disapointed. DC is usually VERY expensive & I know Dennis & his family are working hard; you just need to have accurate expectations and all will be well.