Board Thread:Naruto Discussions/@comment-30168130-20161011015658/@comment-3965545-20161029204537

Seelentau explained that Jiraiya's only problem is that he didn't perfectly balance the chakras, in turn he gained body alterations that he can control. So his Sage Mode is not inferior to Naruto's outside of the chakra control part. Jiraiya was indeed old as Tsunade was 50-51 when she Said that "Kabuto may be better than I was in my prime.." She is an Senju/Uzumaki hybrid so if SHE is not in her prime at 50-51 then its safe to say that NOBODY is. Therefore Jiraiya was not in his prime from the moment he was introduced in part 1 until he died in part 2.