Well, for a supposedly "dangerous and outdated" ATC system...supposedly inferior to even the Italians'....it certainly moves a lot of aircraft without mating any two. More aircraft then the rest of the world combined I might add, and in routine severe weather conditions that would bring other, meteorlogically placid places to a screeching halt when the first echo appears or the airway might become mildly congested. This is not supposition, I watch it happen. The Eurocontrol system is designed to keep people on the ground.
The U.S. ATC system is based on a structure designed for flexibility, especially from the Rocky Mountains eastward because the frequency of convective weather patterns necessitate it if any amount of aircraft are going to fly. The TRACONS deal with the same issues and concentrated traffic, with less airspace. NY TRACON not only deals with EWR, JFK, and LGA, but also HPN, TEB, and sits in the middle of the Northeast Corridor. On a good day, it's busier than anywhere else on earth. On a bad weather day, perhaps with lines of CBs bearing down from the West as they do every few days or so for half the year, they adjust, because everyone from Wash DC to BOS is having to do the same.
For those supposed "experts" on the other side of the pond who think you could impose the UK/Eurocontrol system in that environment and have it work, then you've obviously never sat in an ATC facility and watched your own, let alone any in the U.S.
But when it does breach it's own criteria for safety and loss of seperation as in the BOS incident, through self-reporting, whistleblowing, and constant review by the FAA, NTSB, and OIG, the U.S. ATC system airs it's dirty laundry...even to the public.. and tries to self-correct. Non-reporting in other countries' systems does NOT equate to being "Safer" or that events don't occur.
Having flown extensively in the UK ATC system, please don't try and tell me that the ATC mistakes I've experienced never happened. They have, and I expect they will again. I just don't indict the entire system for a lapse in human performance when otherwise it works for the UKs/Europe's semi-busy, but placid environment.