I put in bold the areas where we disagree.  The more video I watch of Chet the more glaringly obvious his slow feet are.  He's really smart so he gives guys a ton of room on the perimeter because if they pull up even though he's not right on them they still get their shot blocked.  At the same time even though he gives himself that room, he still gets blown by a lot even by bigs who he's covering out there.  He is able to recover using his length and he does move his feet really efficiently.  I just don't see how these tricks keep working at the NBA level.  I think when he gives guys with higher release points and quicker releases that space their shots won't get blocked and I think when he gets blown by which will happen far more in the NBA than it did in the WCC and it happened in WCC play a lot, he won't be able to make up for his slow feet with his insane length and get those recovery blocks that we've all been impressed with.  He's really smart and he definitely moves the right way, so maybe I'm wrong and his fundamentals will make up for his lack of foot speed but again, we really disagree if you think he has foot speed that's at the same level as Jabari and Paolo.  I think his feet are considerably slower.
Then there's the fact that if you're not playing him on the perimeter, how is he going to handle grinding with NBA bodies down low and I don't think he can handle that either.  So I think he has some amazing qualities like his defensive timing, positioning, feel for the game and even his jumping ability for someone his height but I don't know if without the right kind of guy around him (a fast and strong post player that doesn't necessarily have to have great length) if he will be able to get past his defensive liabilities.
On offense I think he's amazing to watch because he is the one that gets to dictate the pace so his foot speed really doesn't have to come into play.  He puts himself in the right spots on that end of the floor too, he has a great hesitation that helps him get by his guy.  He hits the open three at a great clip.  He both sees the floor well and executes passes at an extremely high level for a big.
I just think putting him in the front court defensively with someone who isn't really quick and really strong is kind of a non starter for me with what I've seen.  Nurk also happens to have slow feet for an NBA player... neither of these guys have slow feet for your 90s NBA center but the game has changed and while we can survive with Nurk, he has to have a bunch of guys around him that are really quick and can switch onto smaller guys without getting burnt because Nurk definitely can't and I don't think Chet will be able to at the NBA level either.