Stayed there two weeks ago for my honeymoon for three nights and loved our stay. Haven't stayed at the MO, so can't compare to that although we did stay one night at the Peninsula and hated it. I haven't stayed prior to his departure so I can't really speak to that either, but the stay was excellent. We stayed in the Mae Nam Suite. Hard product was great, but there is construction going on in the outdoor dinner building (adjacent to the pool and by the river). No noise or anything, but the work was noticeable. I think I saw a sign saying it would be completed soon. Dinner was therefore served on the pier at night. Our butler Than was great and anticipated many of our needs including fixing my sim card issue on my phone, ordering cars for us without us asking (we had dinner reservations we informed them of prior to our arrival), printing out maps and copies of our passports, setting up the boat pick up etc. They also were considerate of our honeymoon and set up the room to that effect, and constantly congratulated us anytime they saw us roaming around. They anticipated our early morning departure and had breakfast boxes ready for us as well which was nice. All around it was great, and will probably be my choice hotel if we ever return to Bangkok. We also stayed at Amanpuri, FS Golden Triangle, Anantara Chiang Mai, RC HK, RC Tokyo, and Aman Tokyo during our trip. I wouldn't compare the Siam to Amanpuri, FS, or RC in terms of service, but I do think it was better than Anantara. I think the only critique I would have is that while they are eager to help, sometimes language issues get in the way (something I did not notice at any of the above hotels). Nothing bad or anything, and I wasn't bothered by it at all, but just figured I'd point it out.