Offense: B+. Won some games, was a big scorer, but also missed out in the clutch sometimes, including vs. the Lakers and more athletic teams.
Defense: C-. Sometimes tried. Sometimes contributed. Most of the time camped under the basket to pad his DREB stats.
(Meanwhile, Millsap hustled on both ends--and PM ended up scoring (and blocking, stealing, offensively rebounding, and fewer TOs) at a higher rate than CBooz during the playoffs.)
Average: B-/C+
Millsap + AK + scrub at the 4 > most of the minutes by Boozer at the 4. See also the win streak when Boozer was injured two seasons ago. Now Millsap is smarter about wear and tear (less fouling) and is a better player overall.
With Boozer, difference is somewhere an improvement of one or two playoff spots to a downgrade of one or two playoff spots.
The replay supports it, and the games support it.