I can confirm that EWS is definitely a weaker take against a primarily big-ship fleet.
The game I did a few days ago had my opponent use an assault frigate with EWS equipped against my decked out cymoon 1 with intel officer, XI7s, spinals, and IF!.
It still only took two rounds of firing into the same arc to destroy his ship, and that was on his EWS chaff'd side arc. I accuracied his brace both times. Had he been running ECMs, I'd have to use my intel officer on his brace, he'd get to use his brace once, and then that might drag out the shooting for another round, which means he'd have gotten to shoot my ISD one more round.