Thomas would also do retcons that created more diversity in the golden age. In ASS he created a female Firebrand that I thought worked out pretty well. There was also Amazing Man who had a decent power but a crappy costume. Towards the end of the run he also gave Liberty Belle sonic powers and a cape. Can't say I really cared for that change but did like Tarantula's new costume. His Marvel version of JSA he also created one of my favorite retcon heroes, Spitfire.
As for Don Heck being a terrible artist, back than I would have very much agreed. My JLA subscription started when he started and I felt cheated. There was something about the way he drew eyes that I really disliked. Now many years later I actually feel a bit of nostalgia with some of his runs. I look back at his Teen Titans and Batgirl work with fondness.
