Depends on the ships really. Generally speaking Centauri vessels aren't as out of whack as certain skirmish level missle launchers favored by a primitive race that doesn't even have artificial gravity, but on the other hand a lot of their ships are either a tad too strong(Sullust, Tertius) or noticably too weak(Haven, Kutai, etc). Part of the problem is that the high end Centauri ships tend to have some nasty beam weapons with lots of dice, good range, and a forward arc. It's rarely durability that's a problem. It's beams. Lots of beams.
On the opposite end you have the crap like the Haven. Why the heck would anyone take a Haven? Is there a patrol level ship out there that's worse than this pile of crud? There are some patrol ships I'd chose before the Haven even if you were giving me two Havens at the cost of one Patrol point. It's that bad. The other crappy Centauri ships aren't quite as bad but they're still really crappy.
The Centauri do have quite a few balanced ships. You just never see them because of the unbalanced ones. Why take a good ship when you can take a borderline broken ship? And definately why take a crappy ship when you can take a borderline broken ship or if not that a good ship?