The shield transfer is still plenty powerful, it just isn't op invincible shield mode any more. Novas are still OP, but I am finding ways to counter them (long range Acheron spam with shield transfers is one such way). On anything with a nova, either close in or aim for weapons - then ova takes crits more often than most other weaponry.
I think the issue with novas atm is their proliferation. A cap on novas (say, 1 nova cannon per classifications - 1 x Cruiser, 1 x BC, etc) would stop it getting silly while not removing the potent field clearing capabilities of the cannon. My issue atm is with 5 x Nova fleets - instant killing assassination targets or breaking lines in two volleys is funny a few times (for the guy doing it) but the issue with computer games is that unlike tabletop, you can't escape 'that guy'.
DISCLAIMER: I am not saying everyone who runs Nova heavy fleets is 'that guy' (I am running them and recording extreme edge cases to submit as evidence of 'flick switch to win' play styles in the hopes of balance), merely using it as a clear point of reference for people many of us may have experiences with - those who think that competition is all about salt, humiliation and crushing people without any sense of the game itself. When a game becomes 'flick switch to achieve victory with possible bonus of aggravated opponent' its basically just a breeding ground for those who would get into the deployment phase of tabletop before their opponent, seeing a line of novas, will shake their hand, wish them luck and concede the game to go play a proper game.
I really hope that the general good tabletop vibe I have been getting is complemented by dev experience that the Internet is the final refuge for 'that guy'(tm) and that if they want fleet diversity, restriction on proliferation of powerful weapons would be more potent a balancer than nerfing - nerfing will just ruin a thematic and cool weapon system while letting 'those guys' move on to the next trick.