So the general consensus is in, and it is: Mckay is great, everyone else has been bad lately. I can't dispute that McKay has been playing great basketball since he's been eligible, but there's a couple things to look at.
McKay didn't play as many minutes as I thought against Drake and MVSU, but you could tell he was playing his game and was the focal point when he was in there. McKay had only 2 fewer FG attempts in those two games than Niang (25-12 Niang in the two since). So Niang and others were facilitating, while McKay was playing his game, warming up after 1.5 years of not playing competitively. That gives him an advantage. Everyone else looked like they'd been off for three weeks against South Carolina while McKay looked ready. I think this has much to do with it.
McKay has improved the defensive efficiency. It's gone from 84th after the Drake game to 56th after the Oklahoma State game. He's meant something on that side of the ball. He is a shot blocker (7 through 3 games) and a shot changer.
That said, I think ISU was gambling too much against South Carolina. Everyone has bought into McKay being a rim protector and the team maybe too much. Where the team had excelled before - shading players' strong hand, staying in front, guarding the baseline - all seemed to break down in that game. The fans are excited, the players are excited about a defensive changer, but I think the benefit will show most when the Cyclones play their style of defense on the perimeter and let McKay erase some of the mistakes (which aren't hard to find). Let him be a defensive backstop instead of putting everything on him.
As an offensive player, he's been as good as advertised or even better. He's had 38 points in 84 minutes, or 13.5 points per 30 minutes, as has been pointed out before. He's had those alley-oops, he's had those dunk put-backs. He's had those dunk and fouls. Sure his FT% has been poor (42.1%) but he's been making a lot of the shots on which he's been fouled. McKay's running of the floor will have other teams compensating. And his rebounding has been helpful.
Here's where I think McKay hurts a little bit, on the offensive side. The previous two years, Georges had been the tallest (and heaviest) man on the court for the Cyclones. So the other teams tallest, and heaviest man, usually guarded him. Because Ejim and Hogue and others were outside threats, they could take their men out to the three point line and let Niang work one-on-one against the other team's center in the paint. Georges can get his shot off against one person bigger than him and have success. Through two games, it looks like the increased quickness of the other teams' 4 and the size of the other teams' 5 have been tougher to overcome. He's struggled some down low, since McKay has been in the lineup.
Here's how to fix that. When Georges is going to be isolated down low, which is often, McKay should start working his way out of the paint. He'll give up the offensive board opportunity but hopefully the other team's big man will follow. If the other team's center stays low, McKay isn't a threat to shoot from outside (I don't think), but Georges is a good enough passer to get it to him. Hopefully this triggers a reaction for the defense, and McKay can swing the ball around to shooters. I think McKay is a good enough handle to make this work. It might even help, if McKay moves outside and toward another ISU player. Niang gets the ball to McKay, someone help defends on McKay, he gets the ball to someone else, and there might be an opportunity to get the ball back to Niang in the post where he can do work.
Fred's half-court set, his transition offense is all built on spacing. I think spacing makes Georges work. Even in the pros an iso can't work if defenses are sagging. If McKay can show any ability to either make a 15 ft jumper on the baseline, or be able to work the ball around, it will open up Georges so he can work more efficiently down low.
All that said, McKay has added an unique element to this team that hasn't been there before. His ability to rebound, run the break, block and affect shots, is really something this team hasn't had before. I think it's just a matter of spacing on the offensive side of the floor and Fred is the right man to make it right.