The flat was big enough for two people but it would be a squeeze for more, the ceiling height for the bedroom wouldn't be good for anyone over 6 foot but I had no trouble, the WiFi worked well, the location is great, and the person who greeted us was nice. I didn't find the bed comfortable, and the air conditioning worked well but was very loud.
I initially tried to cancel for a full refund. It said if you cancel by noon on a certain date you can get a full refund, I tried at 11:40am-ish UK time but they then implied local time. It didn't say local on that part of the listing.
So you are aware a few days before you have to check in via Clean BnB.