Do tanks actually take less damage?

[booleansphinx]

I know warriors get defensive disc, but outside of that is there any significant difference between a Paladin/SK/Warrior and a Bard?
They get the same defense skill cap and can wear the same armor type. Pre-50 even clerics have the same defense skill cap as Paladins and SKs. Seems kinda weird.

Is there some sort of hidden advantage tanks get that makes them useful for taking hits or should people actually just have the highest AC person in the party tank?