I have received one of these boards, with another on the way.
I can 100% confirm that the keycaps are PBT- they even have 'PBT" etched on the insides!
The form-factor is fantastic- I prefer it over a TKL board as you still get all the keys but in a smaller form factor.
The MY switches aren't much fun for typing, but for gaming they are great.
Overall, very happy with the purchase :-)