I know all my character gains the rested XP and not the class. But my question is does the rested xp equal out in numbers not % of the bars?

i.e. My lvl 35 gets 100k rested xp, will my lvl 1 get the same 100k or will his drop to 100xp?

So is it best to use the rested on my higher level to get max benefit?

Thanks