Pickup Question: when a maker says "our pickups don't play well with other pickups"

[Help!I'maRock!]

I guess that sounded wrong. I meant that they are a pretty unique sounding pickup and you'd probably find it hard to find something that meshed well with them. They are....the best way I can describe it is a hi-fi pickup. The opposite of a P90, say. They have a really wide dynamic range, tons of bass, tons of highs, really balanced, loud and super clean. I'm not sure a humbucker would sound right mixed with one. I could be way off. I usually am.

EG

your description is consistent with what i've read from others. but i still think i need to play them first. the problem is, where?