I have the same position on Carroll at $15 million as I do on Khris Middleton: both are very good players, but don't do it.
I give Middleton a huge edge based on upside. He's 23, Carroll 28.
At the same time, Carroll is more proven. Regardless, I don't think it's a good idea to give either a max / near-max contract.
I'm not so sure Carroll is more 'proven'. Two seasons ago he was average 6 points a game. He's always been a solid defender I guess.
Your position is to save our money for a marquee free agent which is appreciated.
I'd be happy with giving Middleton 15 million because I think he's going to get better given his age and experience, and if we are going to throw 15 million at Carroll or Middleton I'd pick Middleton all day.
There's always the risk of injury or post contract year decline but if you've seen this guy in interviews he seems like someone who's worked his butt off to get back from once being a lottery prospect who hurt his knee and went in the 2nd round, to an up and coming top 50 and potentially top 25 NBA player.