I think 3 days in each place is good. In Seoul - try and get a hotel near the Myeongdong area. I stayed at Hotel Venue G. It was within 30 min walking distance to most of the interesting places like Insadol, the Palaces, the temples, Tapgol park, the shopping areas, Money museum etc. The metro stations were within 5 min walking distance. For Hong Kong, I preferred Hong Kong Island over Kowloon. I stayed in Harbour Grand hotel in North Point. It was a pricey hotel as I was with my family. I am sure you can obtain a more economically priced hotel in the Causeway Bay area. This is a lively place with lots of eating places, bars and shops. Give yourself one day to visit Kowloon. The star ferry runs frequent services between Hong Kong and Kowloon. In Kowloon you will find Kowloon Park, Nathan and Chatham Roads, the avenue of stars, promenade (to watch the light show), Jade market, many shops and eating places, museums. Spend another day going to Macau on the early morning Turbojet ferry and returning in the evening. Best to book tickets in advance and online - so that you get cheap tickets. Otherwise, you will pay for more expensive tickets if you go to the ferry terminal to buy tickets as the cheap ones are all sold out. Spend another day in Lantau Island. Take the yellow metro line to Tung Chung. From here take the cable car to Ngong Ping Village to see the Buddha and the monastery. From here take a bus to Tai O fishing village - and return to Tung Chung by bus. If you need any other information, let me know.

a. 4 days 3 nights should be plenty . b. Add One more day if you go to Macau. If you do go, catch the “Dancing Water” show which will impress kids & adults. I’m not a big fan of Macau. But, some might like the Portuguese restaurants , glittery buildings Las Vegas style including one that’s a replica of Eiffel Tower. c. If your kids are fairly into Disney stuff then it might be fun for them to stay one of the nights in one of the Disney hotels. Various Disney characters move around in the Hotel restaurants which is nice for kids. Downside : some price premium . d. Use the recommendations on Trip Advsior eg visit the Peak, Victoria Harbour, Ocean Park... Stanley .