Hi zemb,
I've frequent SPG properties in Thailand, and would like to give my views ...

In your search for beach properties, it depends on what your idea of the beach activities you would like to do. If you love to partake in the full beach activities, then Sheraton Krabi, Sheraton Hua Hin, LM Phuket, LM Khao Lak and Naka Island would be a better fit. Naka Island doesn't have as much beach activities, but does have fantastic spa facilities and a proper beach to relax in.

My pick among the bunch would be Sheraton Krabi, Sheraton Hua Hin and LM Khao Lak for their full-beach-resort amenities with full access to beautiful beaches and excellent overall service by the resort staff.

If you just love watching the sea without the beach activities and perhaps no meaningful beach, then Westin Siray Bay, W Samui, LM Samui and Sheraton Pattaya. I've placed LM Samui in this category although they do have access to a beach, it's merely a token sea access with non-existent beach facilities and activities.

My pick among these non-beach resorts would be Sheraton Pattaya, for the excellent service and beautiful view of the Gulf of Thailand over the cliffs.

I've gotten Plat upgrades in all SPG properties so far including LM Samui, which upgraded to a pool-access suite from a verandah suite. Upgrade not available for W Samui.

If you've already made up your mind on LM Samui, then do consider my inputs for your subsequent visits. But personally, LM Samui rates poorly among the list of SPG properties due to the lack of proper beach or resort facilities and their service is rather indifferent compared to the high standards of the other SPG properties. The only thing I liked about the LM Samui is the daily lighting ceremony at 7:19pm. The advertised Kom Loy (lantern) activity was always cancelled due poor weather conditions.

Sheraton Hua Hin, LM Kao Lak and Sheraton Krabi are better resort properties with better overall value as well, in my opinion.