I had a set of Ducky's backlit PBT keycaps, and they were extremely nice. If I had a still used a backlit keyboard, I would have kept them.
Tai Hao has some weird symbols on the caps, num, and scroll lock keycaps that I don't like, and they seem to have recently switched from using the Windows logo to "WIN" text. I'm not a fan of that, either. Otherwise, I really like Tai Hao's keycaps, even their normal thin doubleshot PBT ones.