I've enjoyed the Observation Wheel a couple times over the past year, finding it to be a fair attraction, something particularly enjoyable for those visiting Hong Kong with families. Opening hours are 11am to 11pm daily.
Ticket prices are much cheaper these days (HK$20 per adult, HK$10 for children and seniors and free for those under 3 years of age). You can buy in advance on their website or at the ticket kiosk just near the ferris wheel.
In short, the Observation Wheel is a modern ferris wheel with 42 enclosed gondolas which can carry a max of 8 people. It rises to a height of 60 metres, affording nice views of the Hong Kong Skyline to the south and east and of Victoria Harbour and Kowloon to the north. A full cycle around the Observation Wheel takes approx 5-6 minutes and tickets are usually good for 2 or 3 spins depending on the queue sizes.