It gets to 600-650 
There website kinda made it sound like 550 was tops?
Pellets & environment make a big difference, so they say 550 so people do not hammer them complaining about not getting that hot. People seem to hammer RT for every little thing lately. Mine on max was running over 600 this summer. I usually dial it back to the 500-550 range when I am searing or doing burger/hotdogs.