We had a wonderful stay at Hyatt Phuket.
1) The resort: beautiful main area around the big pool, ocean view, kids' playground & kids' club, leisure area, restaurants, everything is in the same place which is convenient.
2) The room: we had a 2 bedroom with ocean bunk beds. The room offers a lot of space, kids loved their big bedroom. Beddings were very comfortable. The view is on the garden with the ocean being far away.
3) Activities: not all the activities listed on their website are available, do check. We tried snorkelling once but the visibility was too poor. Kids loved the kids' club & playground. The fitness is well equipped. The massage at the spa were great! The beach is small, not suitable for small kids swimming due to the coral rocks (better to go to some other beaches near by). But you can walk on a trail into the sea which is nice.
4) Location: nothing by walking distance, need to take a taxi.
5) Restaurant: very nice breakfast with beautiful views as the restaurant is a bit higher up the stairs. Good lunch/dinner/cocktails too with happy hour.
6) Service: although we had some issues during the stay (Ac not working, slow service at restaurant etc), the staff was always very kind, trying to arrange and solve issues. That made our stay overall a really nice one. We all enjoyed a fantastic holiday and I'd recommend this hotel.