Omicron

My personal opinion is Merrin. Unless you use Admiral alot I don't see his omicron as useful as Merrin's

Agree with emtdrobert. Merrin omi is more useful in GAC, particularly the part that inflicts enemies with plague at the start of her turn. With Mother Talzin lead and Merrin omi, the amount of plague you can hand out is nasty!

The Merrin omi essentially removes the easy Imp Trooper counter to NS.  Generally they can't get going before they get plagued to death.  The biggest benefit to Raddus omi is getting an extra speed point on his ship.  In GAC, RO teams fall easily to CLS.  I never put it on defense.  It works decent on offense against a few teams, but Merrin is by far the better value.