OCA seems to fire faster (as if it had CJ2), I don't notice any change in base accuracy.
ATAC seems to be how it was before it got buffed, but people's perception of it will not be changing anytime soon because,
most of the time, people get killed within the ATAC's original min-ttk range anyway, and will continue to after this nerf.
I actually think you made a very good point about the ATAC ttk range. I belive it was max 40 m before dmg drop off yes? Pesonally I have problems getting 0.7 sec ttk on all targets above 20-25 ish meters (not entirely sure about excact meters ofc...). It can ofc kill out to 50m like any other assault rifle, but it also has the worst accuracy of all assault rifles if i am not mistaken, so ttk increases ALOT. And now they made it a tad bit worse even? Oki..maybe ppl will think its balanced now:)