Just to bring the math back into it, if you have 3 attack dice and either a focus token or target lock available to spend, the distribution looks like this:
Hits+Crits | p
0 | 2%
1 | 14%
2 | 42%
3 | 42%
So Accuracy Corrector has a fairly small effect on your damage if you were already planning on modifying your attack with a token. In that scenario, it brings the average up from 2.25 to 2.42 -- less than 8%.
If you can't modify your attack dice, though, it boosts the average number of hits + crits from 1.50 to 2.13 -- a 42% boost (and the final result is just a bit shy of your average with the focus token). So what the Accuracy Corrector really does is free up your action for maneuvering or defense.
And that means it's most useful on ships that have a lot of choices available for maneuvering or defense. A B-wing with an Accuracy Corrector has a nice, reliable attack, but unless you expect to barrel roll every turn, it's actually a (much) smaller boost to your damage than a Fire Control System.
So from my perspective, it's a powerful upgrade (well worth its cost!) but you're going to want to save it for E-wings, Aggressors (aka IG-2000), or the Virago. On a Lambda or B-wing, you've got better options.
Devil's advocate here.
The Lambda practically requires an Engine Upgrade to be mobile. The Accuracy Corrector gives it a damage increase without the FCS+Gunner combo.
A B-Wing, played for agility (with it's very-red dial) is one of the best knife-fighters in the game. The Accuracy Corrector gives it a damage boost, at the expense of the Advanced Sensors that usually fits this build.