Aside from the glitch where you have to alt tab to enable crossfire, I've noticed that crossfire actually drops out o.O. I was playing and it was great, suddenly however it felt like the game became epic laggy. It was a round later I noticed that crossfire had dropped out o.O. I alt tabbed again and it went back to normal.
Da faq.
-Other sources of input lag:
teamspeak (Bitey/Sdub)
In game vsync (tons of people)
connection (tricky to check for somethings)
frame latency (fixed by capping fps or using dynamic/adaptive vsync)
Good to know some other sources, does server poling lag still affect the clients?