in my Opinion:
Save your T6 ship selection for the new ones coming.
If you play a DPS build, try a Negh'var.
IMOHPO, it's better than the Marauder, compare it side by side in the shipyard and you'll see the differences.
The Varanus has issues with it's repair platorms, I would recommend wait for a fix...
Other than that, it's alright, But I persoanlly prefer the carrier.
Guramba does look totally awesome, but, it's pricey in the Cstore and that's the only way to get it.
And, in the long run, the Raptor's a better escort. Guess it depends on if you want effectivness or cosmetics.
If want a Science ship, the Klingon carrier is still probably the best choice.
Despite it's slow turning rate it's a sturdy ship in PvE, in PvP it must have good team support and it'll perform well.
And, there's always the BoP set up for Science, although with it's very light hull it takes a different tactics to be effective.
With the new set up of the shipyards, it's very easy to side by side compare any ship.
Consider all your options.