Ok, the WWH fight was different then what i'm talking about. The Sentry released all of his energy pointing at one subject (WWH), but that was hardly letting himself go. First of all, he encased them in an energy vortex so that no outside humans would be hurt. He also stood there and took punches from the Hulk while laughing and not fighting back. Yes, he was still releasing his energy on the Hulk, but he was hardly fighting to the best of his ability. He was drunk on power and needed to release it. He new the Hulk was the only person that could take its release.
For a character that was going all out,,,,he has way better feats than that.