Stats like OPS are just "easier" to find, as silly as that sounds. When I click on a player page, OPS is there, but not RC27. When I click on league leaders or team stats, I need an extra step to change it to extended stats. Again, I know that sounds silly.
I also have a better grasp, at least in my head, on what a good OPS is. A .850 OPS is a very good OPS. What's the equivalent RC27?
RC27 may be a "better" stat - maybe I should look at it more.