Is it cheaper to catch the train and free shuttle to hotel in kowloon or take a taxi with 2-3 people in HK?

If you have three people, taking a taxi direct is cheaper.
If you have only two people, taking airport express and free shuttle bus are suggested. In this way, you can just take the K4 to Park Hotel and then walk to your hotel.
in my opinion, the cheapest method is to take airport shuttle bus line A21 to Granville Road, Chatham Road South and you can see your hotel after you get off the bus.