In a pinch the AI is very good at soaking every kind of damage the most efficient way, and it always seems to have that bit of flux breathing space left to flicker its shield on for every single hit of my intended armor and hull killers.
Then I back off to the edge of my weapon range, and the AI suddenly turns its shield off, taking several massive hits before turning it on again. This especially happens in 1v1 simulations, which tends to make them kinda useless.
I particularly like reactions to asteroids. "CRASH - Oh an asteroid, shields on! Path clear, shields off....CRACK - Goddammit, another asteroid, shields on..."
On the other hand, I love how AI ships protect each other by throwing their shielded selves in the line of fire for a moment. Sometimes a tiny frigate sacrifices itself in vain, but most of the time it works and it gives the fleet operations so much more life.
To the point: dedicated anti-armor and especially anti-hull weapons pale next to shield killers. If a ship is already taking hull damage, it is doomed most of the time anyway. Armor and hull are finite resources, if you are consistently able to nibble at enemy armor and they aren't capable of that, you are winning. Dedicated armor-destructors may make this faster, but also less reliable. And if you are just scratching their armor, chances are that weaker anti-shield weaponry will make those scratches even less likely. And if you are already destroying them, do you really need that happening faster?
Missiles are completely hopeless, as they face PDs in addition to shields, and surrounding hostile ships can help your target with that as well. Bombers can deal some serious damage if they happen to hit an unshielded side, and that is entirely up to them right now.
The best way seem to be sustained fire to spread damage evenly over time, so that the target simply has to take your payload exactly as you composed it without picking what to block with shields and what is better soaked by armor. Burst fire ballistic weapons are okay too, as they are able to clear the last bits of shielding for themselves.
I do like the fact that the AI can use the mechanics well, but it renders a minority of weapons superior and far easier to use regardless of circumstances. "I'll just point my tachyon lance(s) at it until it explodes."