This is exactly the type of player the C's should be trying to sign. Young, undervalued, still with top level talent. I wish he was a better shooter, but there is still a ton of talent there. He can handle the ball, pass it, get to the basket, and he is a tenacious, although not great defender. More than anything though, he is hyper competitive and a leader on the floor.
Turner actually has a lot of the same characteristics that stand out in Smart. Super tough and competitive guy (sometimes to a fault), who will do whatever you ask of him on the court...but he wants to be on the court.
Offensively, in some ways he fits in well if they are going to trade Rondo, because he can share ball handling responsibilities with Smart from the SF spot. Unfortunately, his lack of shooting prevents him from being a perfect fit, but that could still improve.
I think the biggest problem with Turner so far is that he has the skillset of a guy who needs the ball in his hands. While he can do the little things (rebound, defend, pass), he is not a good enough shooter to play off the ball. But he also is not a good enough scorer or passer to play on the ball full time (very similar to Igoudala). So, he is kind of stuck in no-mans land. This is the biggest problem with him in Indiana. He is not good enough to take the ball out of George's or Stevenson's hands, but he also is not a good enough shooter to spread the floor from them. So, he basically became useless.
If you can bring him in on a cheap contract, really get him to put up a ton of shots a day (just like Smart), and then basically let him and Smart go to work and develop next year, this could be a great chance to build value quickly. And I really don't think it will hurt to have another ultra-competitive guy in the lockerroom.