The communication and the check-in process were a disaster. In short, Sonder changed our location without informing us, and it took an hour and a half to get things ironed out on arrival, including having to get to another location.
Details: We had not received check-in instructions 3 days in advance as promised in our confirmation. When we arrived we called Sonder support. They said we needed to upload a government ID thru the Sonder app. So first i had to download the Sonder app. Then the app needed to take my photo to match it against my driver's license, but my camera settings weren't set to talk to the app. Fortunately my friend figured out the tech. (What would someone do if they didn't have a smartphone or someone tech savvy with them?) Finally we got the key code. We kept support on the phone until we got into the room, anticipating there might be more issues. We were right. The key code didn't work. Then we were put on hold twice while they figured things out. They asked which address we were at. We said St. Charles. They said we were supposed to be on Rampart, a different location - in fact a different address than what I had reserved AND than was in the multiple confirmations I had received from Airbnb. We had to walk another 12 minutes with our bags to get to the right place. This whole episode took 90 minutes. We requested a partial refund for our troubles but they only refunded us $150 out of a $1600+ bill.
As for the place itself - it was very nice. Sonder "upgraded" us to a 3-bedroom, 2-bathroom (nice, but we could have had another colleague stay with us if we had known. We were there for a conference.) The place was very clean and cool with high ceilings. It was quiet at night and had a secure entry. There was no terrace as advertised, however. There is a very neat bar called Dovetail on the first floor but we didn't take the opportunity to go, it would have been great if they were also a coffee bar in the mornings.
I gave it 2 stars because of the awful communication and check-in. Airbnb should not be working with groups like Sonder.