I'll be going end of January - early February - soon!
For Bangkok I'm mostly narrowed down to Athenee or SGS as the best well rounded experience (good morning and evening food & drink options, modern, but low suite upgrade chances), or St. Regis if I want to focus on service, best chance of suite upgrade, and excellent spa. I've heard people mention that there is no mango at Athenee - any chance you've noticed if that is/isn't the case?
For Phuket, I think I'm mostly looking at Marriott Nai Yang (generally gets decent reviews, looks modern enough, breakfast buffet looks great with fresh mango, but beach recedes away and that makes people grumpy?), Naka Phuket (kinda beautiful, lovely villas, but likely not really what I'm looking for ...), or Renaissance (fairly well rounded, again great breakfast with mango and ice cream, fitness center looks amazing, free bikes to get around, but hard product slightly less good than others I'm looking at ). You mentioned staying at Marriott Nai Yang Beach before - I thought I saw something about an elite cocktail hour, but now I can't find that. Do you recall anything like that?