So it's true that carriers weren't powerful enough.  Now they are too powerful.  It's actually arguable that you don't need to build anything but carriers, this is due to the ineffectiveness of defense vessels at defending the fleet.  While the defense vessel won't succumb easily to a strike attack, they aren't particularly good at shooting down strike craft either.

I suggest first of all that you look into this.  Carriers are usually meant to be a powerful but weak ship that needs to be protected by the rest of the fleet.

For Carriers: Reduce their shields and hit points, or reduce their armor.  Reduce their mobility, all ships have a disadvantage currently carriers do not have a weakness because they can't be caught and they have enough hit points and shields to survive a lot of damage.  Currently any regular attack ship can't get close enough to a carrier to take it out because they both move at the same speed.  This gives carriers an overwhelming advantage as they can just wait for their fighters to destroy the craft pursuing them.  Increase the build time of strike craft by a large amount, and have the carriers spawn automatically with one fighter and one bomber, but give the option to change that ratio. 

Currently carriers can build strike craft faster then defense vessels can shoot them down.  To protect against this, you basically need 1 defense vessel to protect each ship you have in the fleet, and even that doesn't work very well.  Perhaps it's a problem with the ability of defense vessels from hunting strike craft, or that their maneuverability is too low to make enough hits.

In the current release defense vessels can protect a fleet quite well against strike craft, I think it's at a good balance.  However since then defense vessels have had their dps reduced almost by half, while at the same time carriers received twice as many strike craft as before.  This obviously gave carriers a double bonus, as other ships in the fleet don't have any ability of shooting down strike craft.  These two changes made the carrier the single most powerful ship in any fleet to the point that if you made a fleet of carriers nothing but another fleet of carriers can stand in your way.

One last thing, please provide a method on Impulse to change back to the current release from the beta.  The carrier unblance, removes a lot of fun out of the game and I find myself loosing interest in playing.  I would like to switch back to the current release without having to download it all over again.