Sonder on Boylston was an awesome stay. If you're looking for a secure place that's clean and centrally located in Seattle, this is the place! Lots of nice eateries, shops and transportation near by. We walked pretty much everywhere (40 min walk to Lumen Field) but the streetcar is only a few blocks away as well as well as other public transportation options.
There is a nice lounge right off the main entrance, as well as an essentials cupboard in the hallway (toilet paper, tea, creamer, plates....etc). We were able to move around the property securely and the staff was friendly and helpful.
If driving I would be mindful of parking. We got there late in the eveningon a Friday night, so we had to do garage parking that night for $15, then out by 7am. I found a nice spot right by the main entrance of the property, then just paid through the app provided on the street parking signage. Keep in mind that you can only pay on two hour increments.