BLM speak...
Solitaire = Free. Helps with Sorc Activation, Saves gil, decent back piece overall, if you don't want to spend 300k.
Ixion = Easier to cap Stoneskin, but there are plenty of other options for that. Helps with Sorc Activation, and provides almost as much Mag.Acc as Hec depending on mob. -Emn, who cares.
Hec = No help with activating Sorc, unless you have Sol/Ixi/Prism/HQ to put on before you put on Hec, Mag Acc is nice, dmg is the best, overall it is slightly better than Ixion but a pain in the *** to use by itself.