Just stayed at this property again (in route from Bangkok to Phuket to Krabi back to Phuket and on to Bali); stayed two nights at the Westin Siray Bay (again).
We found the service to be excellent; but I have had ongoing problems with the resort's limo contractor.
I also had problem with the LAN cable in my room; which was a simple LAN connector problem but four staff were unable to solve it after hours of work.
Other than that, the suite assigned was beautiful and the room was nice with a spectacular view. The service from check-in to check-out was outstanding even though the resort was very busy (but I can see how non-Platinum or CEM members might not have the same experience).
This is one of our favorite properties; but we have a long term relationship with the staff here and stayed here for a few months during "soft opening"; so we are lucky.
On the other hand, I did leave my car here for over a month (while traveling to other SW properties in Thailand), and frankly most SW properties take quite good car of our car; starting the engine once a week or so to keep the battery in good shape. For the first time, this was not the case as the Westin Siray Bay and we had to spend $100 USD for a new battery when we returned to the property.