Yeah, it was a nice idea, but I don't find myself using it at all. Blind firing seems like a waste of ammo and a gimmick, though who knows, maybe I'll find myself out in the open with one piece of cover to get behind one day.
I got a kill assist by using blind fire last night.... it was the first time I remembered I could blind fire, lol.
In regards to the cover system, it's good and bad depending on the situation, where you are and what you're using for cover.
I'm still using my old skool RO tactics of not using the cover system, but other times, it is handy to use.
If you want to pop out quickly and take someone out, the cover system is good for that.
But if you plan on holding your position for a period of time, (AT, Marksman, MG) then you're more better off pulling back away from the window or other means of cover and hang back in the dark.
An example would be Fallen Fighters. It's great trying to snipe from the many windows available, but if you use the cover system, suddenly your head pops out like a big target with a bullseye on it..... pull back away from the window and suddenly you're almost impossible to see.