We stayed four nights at Coral Rock, situated on the south side of Jambiani. We were upgraded from a deluxe room to a suite - but neither term makes much sense. Our room didn't have any modern amenities except a rather small safe and an AC. The AC was placed in the closet, and it kept the closet nice and cool (at least until one of the frequent power blackouts, then the AC stayed off when the power returned). For the main room there was a ceiling fan. Our bathroom door wouldn't close, the sink was clogged, the faucet was completely loose, and water was spilling from the WC onto the bathroom floor. There was no mosquito net (but malaria is supposedly no problem at Jambiani).
To sum up the room, it was basic and not up to hotel standard.
On the other hand: The place had loads of charm. We had our own veranda facing the sea, and Coral Rock had a small, but very nice pool. The beach style restaurant sat beautifully on a rock above the sea / beach / sea bed (Water flooded the beach almost completely at high tide and retracted a kilometer at low tide). The beaches were white and unspoiled. Breakfast was nothing special, but lunch and dinner were absolutely terrific. At times we had to wait quite a while for the food, but when it arrived it was Oh so good.
If you like the simple life with a pool, beautiful nature, delicious food and a well-stocked bar, Coral Rock might be just right. If you require hotel standard, Coral Rock might not be for you.