This hotel, while stunningly beautiful - is flawed in a couple of ways. It looks amazing in the pictures, and is almost exactly as described, however it isn't mentioned that the hotel is:
a) Far away from the main areas of Chaweng Beach, Lamai and Bophut (Around a half hour cab ride to Chaweng)
b) 500m above the main road at the end of a winding, steep road that most taxis will refuse to climb, and which scooters will have trouble navigating.
These two factors are not the fault of the staff, indeed they were lovely and could not do more to be accommodating, however - the secluded nature of the hotel is not well advertised, and for a person who wants to be amongst the action, you will be much better served closer to town.
If you don't have a hire car, you will be required to book a shuttle down the mountain with reception each time you want to leave and return to the hotel, while there is a timetable of free transfers, if you come back from a late night out, you will have to pay ~$5 for a transfer out of the scheduled timetable.
If you're after a week of secluded recovery time and want to stay in a celebrity-rehab style establishment where you can swim, sun yourself and eat a lot of room service, by all means, Infinity is a great choice. If you're more of an experiential traveller and want to see the sights and truly experience Samui, then I'd suggest you stay elsewhere.