I was designing a Dreadnaught when I noticed the following issue:

Barrier Fields looks to be better than Advanced Barrier Fields (see the 2 screen snapshots below).

You may want to have someone look at ALL of the ship improvements across ALL types of ships to make sure that each new item that is available after researching some technology is better than the previously available improvement. It doesn't make much sense to spend time researching a technology only to find that the new weapon or defensive item is worse than what you already have.