300+
Anything 300+ you get hiccups... Those annoying every 5 or so second .5 second freezes. Actually I think they start popping about 270ms.
I can't stand playing Pantheon when you see someone over 300... Because...
If he's on the opposite team, someone on my team can't take it and eventually leaves...
If he's one my team... I flip out going dude, fix your stuff, or move to country with some better quality internet, and then he eventually leaves...
Either way... What usually happens is the game sucks form the hiccups, or the game sucks because someone leaves and my entire team is AI gold feeders.