I always thought WM worked best in those earlier Avenger stories too. Sort of a reluctant hero who had so much power but also alot of fear and insecurity. Even his costume he had for a long time (the red safari jacket) was a recognition of being a reluctant superhero. Wonder Man became boring after he worked through all his insecurities IMHO.
Here he is from 1986, in the jacket I liked so much too, courtesy of Bill Sienkiewicz (interior story by Dave Michelinie and Kerry Gammill)
I was lucky enough to start reading AVENGERS right when they brought him back as a regular character in the series. And this one-shot was about the time I largely lost interest in Marvel. I can't fairly assess whether Wonder Man got boring after that, since I wasn't reading at that point.
I was surprised to see, when I keyworded WONDER MAN to get this cover, that he had a 29-issue series starting in 1991!
