I ran 13g sliders on mine. Worked fine, mostly obviated the flat spot in acceleration, & a bigger main jet (I forget the size) helped with the rest of that.
I'd consider lighter for a bit more going up hills, but I don't think I'd go heavier, the top end was the same as the stock rollers, & really the bike was pretty tapped at at the top end so I wouldn't see any gain except maybe a little MPG (maybe) if you're kinda light. (I ain't).