Do you mean the Neodymium Deflector Array? It gives an aux power bonus if I remember correctly, but otherwise it's just a preorder bonus like most of the rest - ends up in the replicator by tier 2.
No, at the later levels, you start to see a deflector type called the Neutrino Deflector Array. It even comes in the various colors of rarity. My Klingon even has one for his BoP and it does a good job of rounding out the ship's stats.
You can see 'em available for Dilithium at the endgame item vendors.
Sorry, I should clarify. I know what the main types of deflector do and I know how deflectors work, but this new type seems to have sprung up in season 5.
I cant take a screenshot right now (on my laptop), but an both ESD and Qo'noS the EC equipment vendors are no longer selling regular 'Deflector Array's, but these 'Neutrin Deflector Array's. They have identical specs and icon, but a different name.
What are they for? Is this the new name for a reguar deflector array? If so, did Cryptic just forget to rename the regular ones? Is it supposed to be different in some subtle way?
Got one of these things in a item drop this morning.. It is the the old 'Deflector Array' thats been renamed... This should make searching for it on the Exchange a little easier... (if you search for 'Deflector Array' you get a list that include all the other Deflector Arrays...)
With all the other F2P changes going on, it looks like Cryptic just simply put off changing all the existing copies until the Database issues become more manageable.