Sorry I knew nothing of Gerald Levert, but I'll add +1 to your thoughts about Ed Bradley.
Admittedly, I'm not a big fan of the "main stream media", most especially not the crowd at CBS with Rather, Mapes, and others like them. 60 Minutes always seemed to be a decent news magazine, but too often employed the "gotcha" style of ambush journalism to really meet my standards for what I want in a news show.
With that said though, the journalist I most respected on the show had been Ed Bradley. I don't believe I even know why, just that he did seem to be someone I could trust. He seemed to be fair, yet tough. He seemed to care a lot about the stories he did and the people he talked to and about, and mostly seemed to care about the issues he covered. He never came off as mean or nasty, and never seemed to be letting his own point of view or beliefs interfere in the story.
I was very sad to hear of his passing. I joked with a friend that he was taken while others like Wallace, Rather, Rooney and company were left behind because the higher authority wanted a competent journalist and couldn't find one among that crowd. (Bad joke I know, and Mike Wallace could probably fit that bill in most cases).
Regardless of the bad joke though, I think 60 Minutes probably lost their best in losing Ed Bradley. For that we all should be a bit sad.