has anybody changed their covers and noticed a difference in tone?
i wanted to change mine but i thought the prices for HB pickup covers were a little high, how much positive impact does it have on your tone?

Covers have pretty much 0 impact on your tone.
I will show you something different from either
Your shadow in the morning striding behind you
Or your shadow at evening rising to meet you
I will show you fear in a handful of dust
and if there is any difference it would be impossible to notice especially if you effects between the guitar and your amp