Welding Tips and Tricks

I recently switched from 75/25 to 85/15 AR/Co2 for solid wire steel MIG. I made the switch in order to be able to use both short circuit and spray transfer modes. I am using .035 ER70S6. It sprays pretty good, but when I am using short circuit transfer I can't seem to find a nice "sweet spot". When I am welding in short circuit I can never get that soft crisp buzz or a smooth arc, but when I finish and lift my hood it looks like a decent weld. Is this just the nature of c15 or am I not finding the correct settings? I realize that with less Co2 I will require more voltage in short arc. I have come to the conclusion that I need to bump it up about 1 to 1.5v from the 75/25 voltage that I like. I have scoured the Internet for information particularly a WFS/voltage chart for 85/15 MIG and cannot find anything. This would make for a great video Jody if you are reading this, to compare different MIG gas blends and their effects on penetration and voltage requirements.
Thanks for any help,
Alex

i 2nd that