Since I have been simming I have tried every ATC program there is. I also have flown quite a bit on Vatsim and also spent some time on Pilotedge. My go to ATC, especially when wanting to fly any where in the world at any time is still PF3. Next in line would be Vatsim, but Vatsim is limited much of the day to evening hours in the country you live in. A tyhpical experience on Vastim, especially during the day, is starting a flight once you find a controller in the area you want to fly in, and having the controller sign off while you are still airborne, leaving you on Unicomm with no ATC for the rest of the flight. In the last week I have personally had this happen to me on 4 different flights. When that happens, you have no ATC at all, no AI, no chatter, no nothing. Even when there is a controller, you don't get all the controllers you get in PF3, you normally get a center controller that does everything. PF3 has gotten better and better since I originally purchased it, and every flight now is problem free for me.