I've been debating over which i should get too.
I have a Sharlian maul atm, so any situation where i can use that, i would probably pick it over the 2h prismatic. Once i get an ebon cluster, i'll have ebbc, so i'll probably use that for fights like Drayek. If im in dps mode, i usually have GEBS on + manastone + clarity, so power isnt much of an issue.
Screaming mace for 1hand crush. Right now im stuck with the bloodfire for one handed, so im really thinking i need to replace that.
With the expansion coming out, and combat revamp incoming, im thinking groups arent going to want more than one fighter. So the 1h prismatic would be great for xping up to level 60.
But mostly im wondering if the T5 fabled items are going to be inferior to the T6 legendary weapons. Im thinking the T5 fabled are going to be close in comparison, but im not sure which is going to be better.