I'm no expert of course but they seem almost purpose built to be deployed from Land Raiders. But that just leaves the question, can they do a Raider Rush better than anything else to justify the price?
That's kinda the big question, isn't it? Their main competition is clearly Assault Terminators (and I guess tooled up Vanguard Vets or Honor Guard as a secondary concern, but let's leave that aside for the moment).
To run the comparison between Termies Vs Assault Cents:
1) Same Armor Save (tie)
2) Neither can Sweep.
3) Termies have an invul and access to storm shields.
4) Centurions have more wounds for fewer points.
5) Termies have more attacks for the points.
6) Centurions have shooting attacks (and fairly potent ones against infantry)
7) Termies can run and deepstrike by themselves.
Centurions have a better Toughness.
9) Termies have better Leadership
10) Centurions have higher strength attacks, delivered at initiative.
I think they come out fairly even, frankly. Assault Termies get those storm shields and more attacks for the points, Assault Cents get shooting attacks, stronger attacks at initiative, and are overall cheaper per wound. The *biggest* drawback for the Cents is the lack of invul save, which you can mitigate somewhat with a tough IC to tank for them. I mean, in theory. I'm going to have to try this out.