The studio is located at the back of two houses that are both seemingly associated with the same B&B business (not sure), and up one flight of external stairs above a garage. Our stay was private; a key was left for us and we didn't have any interaction with anyone until we handed the key back at check-out. No B&B breakfast included with this unit.
Access is simple, there is a paved driveway between the two houses that leads to a small parking area. There is a key lock-box option at studio entry so that you don't have to carry your key, but we couldn't get that to work. The main house (not the studio) faces main street, which is a fairly busy, small 2-lane road during the day, but not busy at night and with this studio at the back of the property noise was NOT an issue.
The studio is clean and open, provides a full kitchen, and a small balcony that overlooks the rear patio of the house (but not the house itself) and you can see the parking area to the side. All windows provide nice coverings for light dampening and privacy. We found the bed to be very comfortable along with the pillows and sheets. We slept great once we figured the ceiling fan out. The steam shower is a neat feature, simple to turn on, and heated up the shower space in a hurry. The water temperature and pressure in the shower seemed a little finicky . . . I'm not sure if it related to usage in the main house or what. We ate out so didn't use the kitchen much, but it seemed to be well equipped and was good size.
Overall, we found this to be a good value, comfortable stay, and easy walk into downtown St. Helena. Very pleased. Several good restaurant and even vineyard tasting options within walking distance. St. Helena is a quaint, cute little town, but a sleepy one and shuts down fairly early even on weekends. We took Lyft (and Uber if we had to) everywhere including from the airport and didn't have any trouble getting from town to town, and vineyard to vineyard on our schedule. We found a wine shipping place very nearby the studio, but were a little shocked at pricing - you may want to explore that more ahead of time if you intend to ship wine home.
Suggestions:
Tip envelope for "housekeeping" is tacky when charging. No sign of housekeeping (which we didn't expect or want anyway) until the day before checkout when 2 fresh towels arrived. Just provide 4+ towels to begin.
A book or wall signs for functions (fans, remotes, shower, lock-box, thermostat).