Vortex and Tai Hao both to PBT doubleshot. Dyesub is much better, though.
Like I said, there aren't any quality double-shot PBT caps in production. Dye subs aren't better, they're simply the only reliable option.
I just got a set of Tai Haos in and they're unusable. The 'G' key is offset by roughly a half a millimeter, the '/' key is twisted about 4 degrees clockwise, the enter is twisted about 2 degrees counter clockwise, and the left shift binds on the stabilizers for reasons I can't explain. Previous Vortex sets have had similar issues.