I met him once at a convention a few years ago. I believe that I had a hardbound copy of The Incredible Hulk: Future Imperfect as well as Q-Squared. He looked at me and said something along the lines of:"So, which one would you like me to deface first?"
Yup, that was the humor that I'd expected from him. I thanked him and gave him a Clif bar to hold him over while he was waiting at his table.
I was the only one at his table. I found that kind of sad. After all, this was one of my favorite writers, not just in comics, but Star Trek novels and Babylon 5 (The Legions of Fire Trilogy, long out of print, comes to mind.). He understood characters. He built upon what was there, but wasn't motivated to just "leave his mark." You could tell that he loved writing, the opportunity to inject a little humanity into his characters. This wasn't just a paycheck; it was the act of creation.
Yes, he wrote movie adaptations--and frequently made them better than the movie. I have his version of "Transformers: Dark of the Moon" and it has a very different ending from the movie--and, I think, a better one.
Unfortunately, his last years were plagued by failing health and subsequent medical debt--only partly mitigated by his Gofundme. There are some words I could say about that situation, but I think it's best to be brief (too late, I know).
And yes, I named my UF son after him--a novelist who got himself into a lot of scrapes For The Story. I'm sure that my UF self would have had white hairs from the stress if it weren't for that pesky Detian biocontrol.
Thank you, Mr. David.
--Doc