If he puts the 32 on the rear, and the 28 up front, then it will be like riding downhill al the time

I've aways ridden narrow tires, 23mm/25mm.

I've been playing around a bit with a cyclocross bike. Smoothish 32mm tires? I didn't like the feeling of the first set of tires on it. I now have a pair of X'Plor USH tires on it which I like.

My conclusion is that you may not feel the difference between a quality 32mm tire and a mediocre 25mm tire. However, you'll probably notice the difference between a mediocre 32 and a quality 25.