I'm not talking about the egregious cases which plague German players during the last months. I'm talking about the normal effects cause by the ingame input lag + the physical distance between Germany and USA ping. Add normal human time reaction to visual stimulus.
So it's basically around 0.200ms + whatever delay you get from the game. IIRC that's around 0.500ms/0.700ms for someone in UK.
I never tested my input lag, dont know anything about ping or any related numbers... i only care if i can play the game on any given day or not so i cant answer your question. All i know is that very fast reactions are possible.