I'd definitely recommend this place to anyone who wants to stay right in the heart of downtown & can follow the rules about balcony use.
The location is very central for most of downtown: just a couple blocks walk to gaslamp. We walked to Little Italy in ~35 minutes. Also very easy on/off from I-5 if you want to go farther afield. One other thing to be aware of is that there's plenty of street noise at all hours, so if you're a light sleeper you might want to take advantage of the ear plugs that the host provides :-) .
The place itself is open loft style with lots of neat industrial finishes & big windows. One side-effect of that is that there isn't a ton of sound isolation between the sleeping areas. I'd also suggest anyone who has trouble sleeping when there's a lot of light to bring a sleep mask: there's a big street light right outside the living room window. I can also understand why the host has such strict rules about using the balcony during quiet hours: the balcony faces a tight alley shared with all other units in the complex, and sound can easily echo. On the other hand, sound generated within the unit seems to be well-contained: the walls separating units in the complex appear to be poured concrete; my group never heard anything coming from the neighboring units and we were able to use the TV at a medium volume without any complaints.
Communication was great, even though my group booked this very last-minute. The host even let us check in early since there was no one was occupying the unit immediately before we arrived.