So far I have been using it for "fun" stuff (see below) rather than serious analysis. My focus on the more serious end has been on field positioning and find that the (other than that quite amazing) site Baseball Savant is not very helpful for that (yet?). You get coordinates but no reference system, which also varies per stadium which makes it pretty much impossible to use.
Using Stanton batting data (exit velocity and angle) for fun:
I also started an effort at some point to get some metadata for the Baseball Savant data. It can be found Baseball Savant metadata.
And as much as I find the articles you posted interesting, I don't use them for player evaluation of any kind.