Holding your breath isn't the only element to sway. Your hand wobbles slightly irrespective of your breathing.
True, but holding your breath is going to help you, whereas in Ost, the only thing that could help was resting the gun.
This is going to be pretty important for riflemen and especially snipers, who might not want their gun resting on a windowsill where everyone can see the barrel of their gun sticking out of the window, giving away their position.
It hopefully won't make your aim rock steady, but steady enough that we're not forced to rely on a resting position.
I think much of that was a result of the massively over the top standing/crouched recoil for automatic weapons in RO1. People tended to either sit tight prone/crouched behind cover resting the gun on something... or they charged point blank and sprayed from the hip. Very little in-between.
Hopefully with the more realistic recoil levels in RO2, that wont be such an issue.
Nah, the SMG's are just the most extreme and obvious example, hell, guns like the PPSh where practically useless without resting, you basically had to use it like an LMG, allways finding places to "deploy" it before you could get any use out of it, and it sucked (there's a good reason you saw so many PPD-40's and PPS-43's in use on Ost servers instead of the PPSh, and any smart Ruskie player would toss his SMG to the wayside and pick up an MP-40 the first chance he got, that one was atleast somewhat managable).
But it had an effect on the rifles aswell, i know that i was allways on the lookout for my next resting position in Ost..