Rodimus Prime could be quite ruthless in the G1 comics - right down to executing a defeated Decepticon. Shanghai'd!

Quote Originally Posted by Ode to a Grasshopper
(though arguably the whole of TFTM is his traditional 'heroes journey', replete with learning the value of listening to his elders)
I don't know about that... I still think it was the opening of the Cosmic MacGuffin that made him an instant hero. He didn't really travel there. And it appeared that his maturity was very much reliant on his possession of the MacGuffin, for without it he not only physically reverted into becoming Hot Rod, but psychologically too (i.e. he became less mature). This happened in both the cartoon and the comics too! Although by the end of the Great War Rodimus Prime is Hot Rod again - leader of the Autobots and prefers to be called Rodimus. I can't remember if he was still in possession of the MacGuffin, but I don't think he was. But he still possessed the wisdom and maturity of Rodimus Prime. So perhaps Rodimus finally grew up after a couple of centuries... or maybe prolonged contact with the MacGuffin slowly transformed him... yes Rodimus, it's your Matrix... your own... your precious!