I'm sure he would have done a great Cliff, and established the relationship between characters remarkably well.
I'll always regret that he never did a Superman story, one big 6 or 12 issue run.
I bet he would have played up the fighter pilot backstory for Larry Trainor. Probably write a story where the Negative Spirit is trapped, and Larry has to save the day with an F-16. (Or even more likely, a WWII Spitfire.)