Just a quick plug for Shiatsu-Ya Massage. It was running a couple of years ago from BKK, but now reopened near Intercon Hotel.
Its not a spa, but more like clinic treatment style, the main guy has trained in Japan for 2 years. I think its great! Very intense and professional. Booking is essential.
Shiatsu-Ya Massage
#97B, 3rd floor in Alpha Tower 1 Building on Street 217
Sangkat Pasar Deom Kor
Map Link:
https://goo.gl/maps/6qwY2CTiqwA2
Tel: 012 276 068 / 023 833 544
Email: info [dot] jpmassage [at] gmail [dot] com