Fair enough, I shouldn't have put the "with filler" part. I still stand by the "low quality" (or at least very mediocre flavor) bit though, which still makes the point stand.

When I have a whooper most of the taste is the sauce/bun/toppings with the patty only being responsible for a small portion of the taste, which makes it perfect for a substitute. I've had impossible whoopers a few time, and while eating the whole thing, it's basically the exact same taste. If I eat a piece of the patty with nothing else then there's a noticeable difference though.