I really like those plastic caps!
I float my boards anyways so they do a bangup job of isolating the caps' backs. Diff'rent strokes, I suppose....
As for chinese sellers, I've sourced a few B25k from them but they are really crappy most of the time. Sometimes very scratchy, sometimes all too easy to turn. Mixing them with Tayda's really messes up the pedal feel for me, when one know turns very differently from others.
I know that these pots have a low tolerance but I got a few B25k's from ebay that didn't go past 12k... Tayda's have been remarkably precise so far...