As for an Epic ship to play it has to be the CR90 hands down! followed by the Gozanti.
The corvette I usually run at around 160 points and having good firing arcs along with an almost 360 primary weapon it broadsides and smashes ships! Han Solo is a favorite crew member on this ship.
The Gozanti, comes with some cool cards, Agent Kallus is good and the ability to launch up to four TIE's is awesome, when I get the chance I want to build it as a long range Epic ship killer with a single turbo laser. It's a cool (ugly) looking ship.
For the others, the Raider is also a cool ship with some cool cards plus the TIE Advanced fix and Palpatine. I don't find the Raider as fun to play over the CR90 though it's still a cool sleek ship and positioned right it deals the damage.
The GR75, well after the last two runs, despite having some more cool cards and an alternate X-wing I wouldn't bother playing the dammed thing as despite getting into the fray and causing stress even trying to smash/ram enemy ships was a slog! The last comment was (from one of the other guys using two); "...next time I play Epic and have to take a ship I'll pay the 30 points and load it with nothing and let it sit there."
The C-ROC, I don't have but may pick it up oneday. It also has some cool cards. I came up against it last Epic game though the opposition as I had counted on had little or no experience with Epic ships and thus dropped it out near my fleet while his escort was else where, It was fairly tough, though with only one hardpoint (like the Gozanti) makes it an easy target.
All in all its the CR90...I'd like a 2nd and a 2nd Gozanti and hoping we get another Rebel Epic!