We stayed at Sonder for 4 nights in July. We had a pleasant stay. The accommodations were exactly as described. The building will be even more beautiful once the construction is fully completed.
We used public transportation to get around Montreal. There is a bus stop a few minutes walk from the condo. The grocery store is within a 5 minute walk and restaurants are around the corner. There is a coffee shop across from the building which serves excellent coffee.
If you need to get in touch with Sonder, contact them directly rather than through Airbnb chat to get a faster response.
We will definitely be back.