For my personal games I use 20-80. At times, I've adopted other scales for my dynasty reports based on what I see a lot of people use just to have things have a "common base" -- but I think I'm going to stop doing that.
I've also looked into "stats only" but I've got to read more on it. I always use a full scouting system, so...
Here's a really good article from BaseballNewsHound... a lot of why I use the 20-80 scale is dictated in there.
The Scouting Encyclopedia