i'm in no way putting anyone down or anything but i think that the PIAAs act the same as cheap blue bulbs. meaning the coating filters out all colors except white and produces a bright white light but reduces visibility although it appears that visibility has been enhanced. but if you like them, that's cool.
this is just my opinion based on some research i did a few months ago.
this is one of the best articles that i found. it discusses aftermarket bulbs, including the PIAAs and the reduced visibility.