Johns won me over with "Up, Up, and Away."
Too bad he didn't write all of it, please read the credits again, compare the good stuff there with that other writer that post here and then IC which johns wrote, and you can see where the real credit should go to for making it so good.
Better yet just Compare Superman to Action comics when there are writing them solo.
then compare that to Up, Up and Away.
I know he didn't write all of it. But, his contribution to the story took away any reservations that I had after IC.
I had no such reservations with Mr. Busiek. Generally, I have enjoyed all of Busiek's work with Superman. That includes JLA/Avengers, his JLA arc, Secret Identity, his collaboration with Johns, and his first issue on Superman.
As for comparing. Try this, compare IC with some of Johns' other solo work. IC doesn't hold up to his arc on JSA Classified, doesn't hold up to some of his story arcs on Teen Titans, JSA, Stars and Stripes, or the Flash.