Slot layout and bonuses :

Seven launcher slots vs. Six launchers (both have an empty one to fit a tractor beam or salvager or something else)

Six mid slots vs. eight mid slots.

Five low slots vs. four.

Scorpion Bonus:

Caldari Battleship Skill Bonus: 5% bonus to Cruise and Siege Launcher Rate Of Fire and 5% shield resistance per level

Raven Bonus:

Caldari Battleship Skill Bonus: 5% bonus to Siege and Cruise Missile Launcher Rate Of Fire and 10% bonus to Torpedo and Cruise Missile Velocity per level of skill.

The scorpion has a bit more cpu and powergrid making it very easy to fit however you like it. The Scorpion seems to be a bit more expensive at the moment. But it’s not that much of a difference (about 550mil vs. 600mil or so ?).

Basically if you want a beefier tank, which is very easy to fit, and want to have an afterburner to burn between those mission gates a bit faster, the scorpion is a very fine choice as a mission runner.  Also with eight midslots there is plenty of room for either extra tank or a target painter.

If you’re already tanking missions with ease in a vanilla raven, and just want some extra firepower, the Navy Raven is a good choice.

What you can also do if you have an alt that helps you out mission running, is get the scorpion and give the navy raven to your alt .

Of course the rattlesnake or nightmare are in a class of their own, but it depends for what faction agents you run mission for in case of the nightmare, but pirate faction ships are in another price range I would say ! And I don’t have any experience flying them to compare them against the above mentioned ships.