Right, indeed this one deserves both the "small" part and the "luxury" part of the name, and in fact the small contributes to the luxury as well in a city shock-full of very large hotels especially the chain hotels which are those that I know. On that note, I forgot one point regarding service. In my experience one of the best times for a butler to connect with guests is during breakfast and that is well done some resorts for example StR Bora Bora or StR Maldives, but not as much in big city hotels such as StR Bangkok where I never saw our butler in the restaurant in the morning. At 137P I suspect staff in the Club communicates with butlers downstairs to inform them who has arrived for breakfast because the butler came to greet us and either take our order and/or serve us what we ordered, before giving way to staff in the Club for the rest of the breakfast. It was a nice way to keep the service personal and stay in touch with guests without being overbearing.

Regarding the pool, of all those I have seen in Bangkok yes I would rank 137P #1 overall. I have yet to see Sofitel SO's pool (which I will visit in a few months) which looks nice based on pictures but I think due to overall privacy and how quiet it is, 137P will most likely remain #1 . However if there is one aspect where others might not rate 137P as well is that unlike the pool at StR BKK which has many small trees and plants to give a nice atmosphere to the pool side, the roof top pool at 137P can feel a bit "naked" as the plants are only on the cabana side, not right by the pool. That said the StR pool is busier and does not have the views that 137P has so my personal favorite is 137P, let alone the fact that 24/7 is a big feature for me when getting into Bangkok jet lagged, nothing beats a swim at 3am.