This may prove a somewhat controversial opinion, however with reference to the G1 cartoon specifically, I rather like how Rodimus Prime was written.
Optimus Prime was quite literally a purpose built leader, of whom little was seen between his creation and the point that the G1 cartoon begins. As such, any doubts and misgivings he had prior to fully maturing into the Optimus we all know and love are unknown and a comparison of Optimus' early days of leadership to Rodimus' are difficult.
Hot Rod on the other hand started his day with a pleasant fishing trip before witnessing the death of his hero, almost certainly leading to some long term guilt issues whether he was culpable or not. He was then forced to rapidly mature beyond his care free persona, culminating in him being picked by a force he cannot fully understand to lead a group, some of whom probably harbour some resentment over not being picked themselves to lead and indeed over the whole Optimus incident. Oh and at some point somebody has probably told him that a load of his friends were massacred on a shuttle.
The above would be enough to send most into therapy, however Rodimus Prime has then found himself responsible for peace, not just on Earth but on a galactic scale, which is probably quite stressful.
Given the above, it would make sense for him to have the odd meltdown, to want to be free of a responsibility he never asked for. The fact that even when he has a tantrum, sulks, whines or loses the matrix, he pushes through the issue and fixes the problem, even if only temporarily.
If it were not for these flaws, the guilt, self doubt and resentment, in my opinion he would not be a Transformer, but instead simply a robot.
Also, I like Full Tilt, he is very purple!
