Very tight quarters and minimum privacy. Room hot and stuffy.
You share bathroom with host & partner.
Plan to get breakfast out, minimum is provided.
However, Greenwich is lovely, and worth a full day's attention. The town has many interesting places to walk—the park at the Observatory is very nice.
Getting in & out of London is not as easy as their description sounds; it requires lots of walking. Tiring, too.
Arriving back late at night is somewhat unsettling. Very dark. Nearest train station is not that close to apartment.