Seems like you don’t lose accuracy unless it’s long range. Why even bother ADS with SMG or even Burst?
Aim Down Sight (ADS) why bother?
If nothing else, it zooms in your view a bit and reduces your sensitivity, so it’s easier to aim at a distance. Just a matter of preference.
it does affect your spread as well, at very long ranges consistent headshots are very hard to pull off without ADS.
You do get a slight benefit in accuracy and spread at ranges at the cost of being mobile. So you have to know when it’s best to use it and when to not. I love that it’s in the game but I also love that it’s not the main aiming mechanic in the game. It feels quite balanced and in line with the speed of DB.
it’s a mechanic that puts every bullet you fire exactly where you’re aiming. the trade off is a lack of mobility. if you can’t find that useful then you might want to work on being more creative 
yes, and significantly.
for many weapons it becomes ‘bullets go where your dot is’.
There is still recoil to work with though, and I don’t like how much screen ADS covers.
there is no spread when you ads, but you will have increased recoil (some guns worse than others) and when you get hit you flinch/get aimpunched.
I’m finding ADS useful in more situations than I previously recommended, and think that once sights are added (replace iron sight with red dot for example) they will be stupid strong. Problem with iron sights now is they suck for peripheral vision and the point where bullets land relative to iron sight is ambiguous for most if not all sights.