Someone like Rhino may best be the person to answer this...as he uses the Bscope daily for his stones.
From what I have heard, differences from say..Med to VH will be noticeable, but something like High to VH1 will not. It may also depend on the VH rating. Something like a high High to an almost off the scale VH3 will probably be slightly noticeable.
Hopefully an expert can elaborate for you.