I have a lot of nostalgia-based sentiment toward Optimus Prime. I watched a lot of cartoons when I was a kid in the '80s -- somewhat ironic, since I watch almost no TV now -- and while I enjoyed a lot of the various shows' largely overly simplistic, good-versus-evil stories, and the various "good guys," the good guy who stands out the most in many ways is Optimus Prime. Cullen's voice made him seem like the ultimate heroic leader. He was compassionate toward both those that he commanded and those that he protected, tough as nails when he had to be against his foes, and able to see the big picture while willing to hang with the boys from time to time. (I'm thinking of a scene from the G1 cartoon in which Optimus is trying to play basketball with his fellow Autobots.)
Optimus Prime in the Bay film is much like the Optimus Prime from the G1 cartoon. I'm sure that my nostalgia for the admittedly cheesy yet fun cartoon from my childhood, coupled with the much appreciated return of Peter Cullen, have colored my perception of the Bay character. I probably wouldn't like the Bay version nearly as much as I do had Gary Chalk or some other actor, famous or otherwise, portrayed Optimus Prime. In my mind, the Bay Prime is essentially G1 Prime.
As a kid I hated when Optimus died in the '86 movie. I hated when, following Prime's return, he essentially became a secondary character as the various *masters entered the scene. I hated when the show ended just after Optimus became a secondary character, nixing any chance of Optimus retaking center stage. Some years later, when I watched an abysmally dubbed version of the Japanese Headmasters series, I hated when Optimus died yet again.
Let the guy live. Just this once. Whether he's a red and blue, cab-over semi or a blue and red, conventional semi, he's Optimus Prime, Autobot Commander, the one who should always stand when everyone else falls. And as Stan Bush sang, he's got the touch.