I worked in Hammamet and i loved it but this was a few years ago when Yasmine was just being built. All the hotels were very nice when they were brand new (8 years ago). I believe Tunisia is a marmite resort (you either love it or hate it).
Beaches are beautiful and weather really nice from april onwards. :beach:
The medina is a bit crap but it's worth going into the town of Hammamet for a wander. Yasmine is about a 15 minute (cheap) taxi ride away. Don't go on the Bedouin Feast night it's a pile of crap. But if you are feeling adventurous then they do 2 day excursions down to the sahara which I really enjoyed.