I ultimately bailed completely, and will be staying at the Hilton Bangkok Grande Asoke on Sukhumvit instead. So I'll have great BTS / MRT connectivity and be right next to T21. My favorite place for cheap eats is in their food court; it's like eating at Street Food prices without having to think about getting food poisoning.
Supposedly it's a 5 star hotel. And I was pleasantly surprised that there's a 5th Night Free promotion. I love IHG's 4th Night Free that I get from having the IHG card.