Muzzle loader Scope?

What kind of scope do you have on your muzzle loader. I have a CVA Optima 59 cal that cam with a KOSS 3x10x44 BDC, the yardage markers in the scope is marked or increases by 25 yard. From 75 up to 250, seems like a nice scope, but I was thinking about replacing it with a Nikon ProStaff 3x9x40 BDC.
What do you all think? Should I stay withe the orginal or change out?

>What kind of scope do you
>have on your muzzle loader.
>I have a CVA Optima
>59 cal that cam with
>a KOSS 3x10x44 BDC, the
>yardage markers in the scope
>is marked or increases by
>25 yard. From 75 up
>to 250, seems like a
>nice scope, but I was
>thinking about replacing it with
>a Nikon ProStaff 3x9x40 BDC.
>
>What do you all think? Should
>I stay withe the orginal
>or change out?
I have the same Nikon scope and am pretty happy with it,but I wish it was a Leupold...