Lacey and Larry's place is WONDERFUL. 10/10 would stay again. If their place is available and works with your schedule, I highly recommend.
Not only are they quick, patient, and accommodating with any queries you may have, they are very detailed as well. Directions to their house are hard to mess up, and with subtle signage they provide, the self check-in process is seamless no matter what time you get in.
That detail also extends to the provisions in the room – they seem to have thought of everything! If you forgot to pack something, you can almost guarantee they'll have a small supply for you until you can get to Safeway (which is also very close to their home).
Weather depending, you're also covered on that front. If you go in the colder months, the heat is already going for you, and if you feel a little too toasty, there are a few fans provided. On the flip, if you're extra cold, there's also a small space heater.
The room is downstairs of the house, (repurposed basement space) so you will hear footsteps from time to time (sometimes their dog Maisy is running around) but it's nothing to keep you up at night. I would keep that in mind for yourself as you're stepping down that it's a bit creaky/echoey on the wooden steps — be just as considerate! Boiler does startle a bit when it kicks up, but you barely hear anything otherwise.
Overall, staying—especially sleeping—at Lacey and Larry's has been an exceptionally cozy experience on Airbnb.
Oh yeah and quick note on location: they're not too far from the city at all if that's what you're visiting for, but might still be worth renting a car versus relying on Lyft/Uber. Parking at their place is convenient (always an open spot on the curb) and in general, parking in Denver/Boulder is significantly less painful than other major cities (looking at you, SF). They're also fairly close to a section of the city called RiNo (River North) that has a few great food options. Lastly, if you're not there for the mountains, squeeze a trip to get those gorgeous suckers in. You're only ~1.5 hrs away from them, take advantage!