I definitely wouldn't mind having him, but I think GS is going to keep him. Barnes is gone. Max money for a #3/#4 option isn't worth it when they could replace him with a cheaper 3-and-D type and not miss a beat. You could put Matt Barnes in that spot and I think GS is still 13-0. Meanwhile, Ezeli is their Bogut insurance and if they ended up missing both they'd be in serious jeopardy of getting steamrolled by e.g. the Clippers or the Spurs.
All that said, if he can be had for a reasonable contract, he's in his prime, smart, good defender, true center, yeah would be a decent asset.