As far as I know and have seen ingame, yes. It works the same.
What you said is true, hitting a critical, not only raises the damage by 50% on that hit, but it also guarantee that the hit is a "decent" one.
Theres a debate on how "decent" the hit can be, tho.
For an example, with my hunting set I have a average attack damage of 567, which means that it can go from 0 to 1,134.
I feel like whenever I hit a critical damage, my base damage would be at a minimum of like 50%-60% of my total damage, so I'd never hit below 567, for an example. But that is just MY perception, I'm not sure what the real % is, but I'm 100% sure that there is a minimum.
So yes, critical hit increases more than 5% damage in the hunt :)
I'm sure with runes is the same, but maybe a different minimum % hit on the critical