Well, I am a bit of a noob, but are Marauders good? I was just wondering...

All I know about them is that they are good freighters, and look really cool.

Other than that, I'm clueless...

Marauders are very good. They are the best all-around, do-anything ships. There are better combat ships, but Mauds can definitely hold their own.

However, centaurs usually perform better with cargo. Empty, marauders are still faster than centaurs.

Marauders are great fighters without cargo, and crap fighters with cargo. You can't do both, but you can jettison and fight off anybody that threatens you before carrying merrily on your way.