EZ - the person behind Bill Lawrence USA has only done Bill and Becky bad for years, so I doubt anyone on this board will want to support him or that company.
If you want L-500's, support/buy from Bill and Becky, even if you get chance to get the rip-offs cheap. Sound samples doesn't say much, but I know other makers like to give the impression that they're useful. What about amp settings, playing technique, gain level...sound samples gives very little information about these important factors.
In general, you can use any pickup for anything you like, and an L-500XL in combination with the Q-filter may very well be OK. Use your ears
Mind you, the Q-filter will mostly cut/vary mids, not bass and treble. The inductor (q-filter) is simply an unloaded twin coil, and in combination with caps and resistors it will give the sonic impression that you unwind the coils.
You can even mod a humbucker to act as an inductor in combination with other pickups, but I'll leave that topic to Bill or PeteMk.