I would say it depends, but overall, I'd pick Redick. If I was building a team around "old" Dwight or another center I wanted to force feed in the post like a healthy(?) Bynum, I might be inclined to pick Anderson instead, as his rebounding and outside shooting at the PF position becomes a key part of the offensive game plan and you have someone at the C position that can cover up some of his defensive shortcomings.
Anderson seems to have had an easier road to becoming an effective NBA player though and is a couple years ahead of JJ in that regard. A lot of people said he was only going to be effective along side Dwight, yet there he goes, on the Pelicans, sans Dwight, putting up similar numbers as last year. You could use that to suggest he has more room to grow, and hopefully that growth comes on the defensive end of the court.
JJ has had a tougher road, needing to really work on his game to transition from college to the NBA, but it has definitely paid off, and the work he put in to get himself where he is today speaks volumes about his work ethic.
For a young rebuilding team, I think JJ is a positive influence on and off the court (yes, I'm talking about leadership) and that can't be overlooked either. Maybe the need/desire to retain JJ was taken into account when letting Anderson walk, as well as the desire to go more traditional at the PF position.
Archer: This must be what it's like to have sex with me.
Lana: How can an air-boat be selfish?"