I stayed here for a couple of weeks in late April 2022 and overall it was exactly what I needed. I'd stay there again and would recommend it to others seeking something similar.
The location is great being in the historic South End brownstones and a pleasant fifteen minute walk from Back Bay and half an hour walk from Downtown Crossing. The closest T station is less than a ten minute walk. It's in a peaceful residential area and there are quite a few nice restaurants and cafes nearby to cater to the affluent locals. There are a couple of food stores nearby.
Check-in was seamless with very clear instructions from Stone's team. The place itself is a studio with one large room and a small bathroom. The building isn't a modern-build - the staircase is narrow and rickety which may be tricky for less physically-able folks but I found them very manageable even with a big 12 kg suitcase. Also the walls are thin which some people may find off-putting. Overall the building and studio have plenty of character and I enjoyed embracing the novelty of staying in a brownstone.
The kitchen and washing facilities make this place great for longer stays. Everything you could possibly need is provided in the kitchen. I would recommend to Stone that it be clarified that the dryer costs $2. I interpreted it incorrectly that the dryer also cost $1.50. When I asked Stone why I couldn't get the dryer to work it took her/them a long time to get back to me to resolve the issue. The communication could have been better here.
The wi-fi was very good. No problems.
If you need to work from the room, this is not the place to stay. There is no decent desk or chair to work from.
I suspect this studio would be very cold in a Boston winter, so I recommend staying here in the warmer months.
Overall I had a great experience here and would recommend it.