I've watched a lot of Gonzaga. He's a super interesting player, but has his flaws. He's basically a big playing in a NBA wing's body almost at about 6'8". People REALLY hype of his defense - which is legitimately some of the best there is on the NCAA level... but there are some issues there, starting with his size and reach. His strength is also an underrated issue not talked about a ton... he can get buried more easily than you'd expect inside. He is a great athlete though, and probably moves well enough that he can play the 4 with no problem.
Offensively is where I'm not sure what to think. He's basically a non-shooter and scores the majority of his points inside with a size advantage - something he won't really have in the NBA. He's a super smart player though (better than his ast/tov indicates), so I don't think he'll hurt you offensively besides with spacing. The feel for the game on the offensive end though won't really be that functional imo... I don't know when he'd really ever have the ball in his hands in an NBA level offense.
I think he can be a fantastic glue-guy, but I'm not buying into the upside hype that I've seen quite a bit of. He will turn 23 before opening night of his rookie season. To me, he is very similar to Gary Clark as a prospect. His combine measurements will have as much affect on draft slot as just about any other player I think. His standing reach will be super important for where I'd have him. If it's < 9'0" then I'd have trouble seeing him play much center in the NBA, where his offensive game would be best tailored.