I spend a night in october with my family at the 5 star Poltu Quatu / Jaspe Grand Hotel, because they had an affordable low season offer; 162€ for a double, including HB for two persons, (which is like the price of a three star or even an expensive agriturismo). We didn´t expect much, but it was all great, very nice and helpful people, a free upgrade to a superior room, beatiful place, good food, all in all a fantastic buy!
The surrounding area isn´t really that interesting, you need a car (or yacht...) to get around, or just stay in the hotel area, swimming in the pool, playing tennis, etc. Or just use the hotel - as we did - for a stopover on the way up north to sleep and eat in luxury!

I went there we friends and secured over 5 rooms for multiple nights. The hotel was less than 25% full when we were there. They screwed up some of the reservations and then the manager Giovana would not try and accommodate us but yet tried to nickle and dime us on everything. The rooms were fine and a bit dated but the walls were so thin that I could hear people in the bathroom in the next room over and every conversation. When they put a family of 4 in the next room at 7.30am one more morning I was shocked at how loud it was. With the hotel empty, why would they put everyone right next to each other? The cleaning service never did our dishes in the room which was a surprise since it was an apartment. Check out had 3 extra charges on it that were not mine. Experience was not a 5 star experience. On a positive note, the pool was pretty, the breakfast was nice and Simone and all the other waiters in the dining area was so extremely friendly and very helpful to us.

My husband and I stayed at the Melia Hotel in August 2008 and we had a lovely stay. The hotel is beautiful and the location is so perfect, right on a very classy port about 10 minutes drive from Porto Cervo. The staff was always so friendly and eager to assist us with our questions or our requests. The pool staff consisted of such hard workers. The rooms and bathrooms are very clean and simple but big - which we always appreciate. My husband is Italian and I am American and I had no problem communicating with the staff when he was not with me (which is sometimes a problem in Italy!). Overall, I highly recommend this hotel for anyone.

I have to say, it is very difficult to fault this hotel. From a service point of view, it was second to none. It may have helped that, at least for the first week we were there, it wasn't busy at all. However, the multilingual client-facing staff still provided consistently high service with a reserved, but friendly smile. The maid service was almost always done to a high level, i have seldom seen better - and that goes for the tipping hungry U.S. counterparts too. It was just a shame they didn't understand any English (or my attempts to speak Italian). It would have saved some time in a couple of incidences.
The pool was reasonably big and not particularly occupied. The ice cold nature of the water was a double edged sword in hotter periods of the day. Although there was always enough loungers and a pool attendant on standby.
There was a shuttle (mini-bus) that frequented the beach at set times. Had to wait a bit past the scheduled pickup for the driver to arrive, but he was always on time for the journey back. A word of warning, a mile or so of dirt track leads up to the beach, so it can get a bit bumpy. The beach itself is decent. The sea is crystal clear (but cold like the pool) and there are loungers reserved for hotel guests (although I suspect "outsiders" can hire them). Vendors selling cheap knock-offs are a pain, but to be expected I suppose. Not much in the way of facilities other than a small beach hut cafe a few hundred yards down. This can be a little inconvenient depending on your eating or toiletry requirements.
We went half board, so experienced both breakfast and dinner at the hotel every day. Not as unexciting as it sounds as the breakfast buffet was quite varied (although the juice was from concentrate) and the dinner menu was part usuals and part "menu of the day" so it reduced any monotony. The food itself was gourmet style with mostly decent dishes served up (with maybe one or two concoctions that were more miss than hit for me). The wine list was expensive. Expect to pay 35 Euros for the cheapest bottle of white at time of writing, 7 Euros for a bottle of water.
We also gave the very under promoted spa a go. It took a while to realise they actually had one on site as the leaflet you get from the front desk suggested the location to be elsewhere. Anyway, massages were good, facial for my wife pretty dire. They don't speak English there and the translation from the receptionist suggested they did certain things (steaming, blue light treatment) which as it turned out didn't materialise.
The only downer was the caviler nature of getting us a cab to the airport. They insist on using their own drivers, but he was late and this was after a new later time was quoted after the original one I wanted couldn't be met. Not only that, but he was the proverbial Sunday driver getting us there. No sense of urgency despite my initial statement to the contrary. A metered taxi from the street would have saved a whole load of hassle. Apart from that and the facial, nothing to complain about and everything to praise them for.