EPQ really depends on which unis you apply to in terms of benefits. From what I've gathered from my own experience, most 'top' unis don't really seem to care but some will give you a reduced offer or it will help you get more UCAS points in general.
The main benefit is probably that it gives you something to talk about in your personal statement but I imagine that could as easily be replaced by reading books or engaging in work experience or just keeping up with what's going on and what interests you.
My time management with it was horrible and I personally would not recommend taking an extra A level along side it.