If you click the "See Dimensions" link on either of the webpages you linked you'll get the PDF attached to this post with detailed dimensions for each model; therein are the differences.
Note that the 3220 standard and the 3220TBX have the same base size but the TBX
base is biased more to the
rear of the ball; with the TBX you have
3.5" less distance between the base and the tailgate, the same amount more between the base and the front of the bed.
SO, all things being equal, pick the one with the base location you prefer in light of how you use your bedspace,
the location of the Andersen ball relative to your B&W Turnoverball will be the same in either case (5.5" behind).
FWIW pics are of my 6.5ft bed 2005 F150 with the 3220 standard on a B&W Turnoverball and a toolbox that measures 12.5" along the bedrails; I've got 23.5" from the back of the Andersen base to the tailgate and would not want the 3.5" less that the TBX would provide.
Some will doubtless chime-in advocating for the rail mount version with it's smaller base, but that's a different animal entirely as you know (I love my rail-less bed between towing adventures, I had the turnover ball and that toolbox in my truck for years of towing gooseneck trailers before I got my 5.0).
YMMV, hope that helps, Happy Trailering!