Just back from a Chiang Mai trip and we stayed at 137 pillars.
It's a nice property but wasn't wowed by the experience.
Nothing major, mainly small things like no one at the pool to bring drinks / menus / towels even after hours of staying there.
The kind of things that a boutique property with low key count (and most expensive / second most expensive rooms in town) really should nail.
Will probably check out Anantara or FS next time.