We have stayed at the Beach Haus - Key Biscayne a couple of times now. It is a nice property with simple but clean units, a nice swimming pool and a great location.
Positives:
Location — 1/2 block to the beach and an easy walk to all the great restaurants and shops that Key Biscayne has to offer
Pool - an attractive pool makes for a great, quiet place to hang out on a hot day
Management - Elizabeth, the on site manager is very friendly and helpful with any requests.
Negatives -
The units themselves are very basic but perfectly adequate. They are reasonable well maintained, but not impeccable. The building is older and it shows in some spots. That being said, appliances are relatively new, and the furniture is in good condition.