I did some general analysis on this.
Last year, on my team, the guy who shot the most FT's in the season (not including PO's, or scrimmages or Cup, just regular season).... took 66 Free throw attempts. which is about 3 a game. He shot 0.712 for the year. His FT level was 'medicore' all year.
The guy who just popped to Wonderous FT, shot 0.912 for the year. If my player who attempted the most FT's in the season, shot that percentage, it would have increased his seasons points average from 13.5, to 14.0 a mere half a point per game.
So from Mediocre, to Sensational, level 5 to level 12(?), equals half a point per game. In that example of course.
If that player shot twice as many free throws in the year, then you are talking, one whole point.
OK so if he had only shot 60%, then this margin would of course be a bit more. but obviously not that much.
When i look at it from this angle, it really makes me realise how much of a lack of difference FT's make in the game. Unless they drastically increased the number of FT attempts into the game engine, im starting to think that above medicore is worth.... well.... only about half a point per game. ie: not worth it at all.