My girlfriend and I stayed briefly at Villa Didon in the mid-August low season and had a fantastic time. We booked a junior suite which was one of the nicest hotel rooms I have stayed in and had a wonderful view over Carthage and the sea.
The restaurant is by far the best we experienced in Tunisia, with several dishes I would certainly order again.
The hotel is set away from the town but perfectly located for the main Punic ruins and museum and boats amazing views. However, there is no swimming pool which would be big minus for an extended stay, as beyond the ruins there's not much to do in the daytime near the hotel.
We found the staff extremely friendly, courteous and helpful.
The hotel is expensive: comparable to a five star but without the full range of amenities. However for a night or two luxury and exploring what's left of ancient carthage, I would highly recommend it.More