Agree to disagree. I think Koufos is a substantial defensive upgrade over the current C's on the Celtics roster and provides them with the ability to address a serious need. DRPM likes him a lot, as do
Nylon Calculus' Rim Protection stats. He's a 7 year veteran, but he's still only 25, and big men take much longer to develop than guards and wings. He's fully capable of being a starting C in this league, and has been in the past. Also, just to remind you, we're talking about the return for a half year rental of Jeff Green.
And while it's true he's a UFA, I think he's at a point in his career where he'd be happy to have stability and a starting role and there's plenty of incentive for him to stick around. It's a risk, sure, but its a risk that addresses a clear need.
Also, what's with everybody using the term "overpay" for a contract that hasn't yet been signed? I know it's fun to critique NBA contracts, but the fact that we default to overpay before they're signed is pretty ridiculous.