Well the results of our experiment are as follows:
Replaced the Heavy Fighters ability with one that augments damage, accuracy, and dodge of all friendly fighters in a gravity well.
(Damage: 10%/20%/30%, Accuracy: 10%/15%/20%, Dodge: 5%/10%/15%)
The Sova Carrier, as a single unit, actually becomes less effective. The lack of extra armor on its fighters definatly weakens it, and the addition of dodge isn't quite enough to offset the loss of armor against AA frigates.
However...
If placed in a fleet with light carriers, suddently the Sova becomes powerful, to the point where you actually want to keep it from charging in to the enemy. Its ability to augment the power of all friendly fighters makes a carrier fleet highly effective, and if your enemy doesn't bring counters to fighters (by mixing in AA ships and/or its own fighters) then they can be in trouble.
So far, our experiments find that it encourages a more diverse fleet mix. Take that as you will.