They supplement thrusters, if you apply breaking to an axis it's going to help. (Though it sounds like you know more than me by knowing the proper term!
)
Of course, it's not solely enough but it's their explanation for why they turn so quick.
https://robertsspaceindustries.com/comm-link/engineering/13951-Flight-Model-And-Input-Controls
But unlike thrusters they say that have to actually turn and fire for anything to happen in the physics simulation, the gyro's don't exist they just use it as a reason, so they probably increase the turn rates/thrust output to simulate it having them.
Plus it's like the year 3300 or something. Fuuuture gyros!
I need to try out the latest patch, try the tutorial - I saw a video of someone thrusting upwards out of the tutorial asteroid hangar and as soon as he let go of thrusting the ship stopped on a dime like it had no mass. If they can add a bit of inertia there it'd be nice. It should take just as much time to slow down as it took to speed up with dorsal/ventral thrusters.