Windler plays big. He rebounds very well, and he has good vision on the court. He gets a lot of assists given his role on the floor. That said, I don't know how he fares against a Julius Randle, but I think he can play four on a team with the right mix..
All that said, to the Cavs , he is pennies from heaven if he contributes at all. I think he will have to earn it in the locker room first. You notice in the interviews , the players specifically mention both Okoro and Stevens, when they talk about players working hard on thier games and getting better.. They don't talk about Caris for example, even though it's clear to me that Caris has achieved a step up with regards to his contribution to the team. So Windler, and Merril both, are going to have to work hard to get that kind of respect, which has to come before trust..