I stayed at the Park Royal in April 2013 - this review is well overdue.
The hotel is very unique. The rooms are on the small side per any trendy hotel these days, but the architecture of the hotel is very cool with lots of greenery (hence the Avatar floating island reference).
Service was excellent throughout. Pool side was really nice, though there are some global-trotting hipsters hanging out. View is cool though. Gym was basic but did the job.
Rather than other personality-less 5-star hotels in Singapore, this would definitely be a fun pick.More