Revives in BF4: useless
In the last 3 years of BF4 this is the first time I've ever heard someone say that.
The entire concept of bringing dead teammates back to life is so incredibly powerful that it simply cannot be useless.
I was overexaggerating. "Useless" might be the wrong word for it. "Hannoying" might suit better.
Loading a charge and then puff out because the corpse recognition is buggy, just drives me nuts. Together with standing still (because Loading the charge) open in the field (otherwise the teammate wouldnt have died) is a risky move as well.
It adds up to be a hannoying high risk, unknown reward combination, which needs to be resolved.
Maybe it works better in BF1 now. Does anyone know? AFAIK the Heroin is pretty strong in CQB.