From 'The Joneses' set

"David Duchovny, while a bit more reserved, was just as fun. After spending 8 hours knee to knee on a couch, I can tell you that he is a cool as can be. I never watched X-Files, I am more of a Californication Duchovny fan (That is a killer show). He was very laid back and fun to do the scene with as we riffed on the dialog never doing it the same way twice. Sometimes directors hate when you do that, but some funny stuff was coming from it so it was all good. We all know that Duchovny has a lot going on in his personal life, but he didn’t let it effect him on the set as he was a cool pro. "

Steve Barnes,about David Duchovny's performance on set.
http://barnescreativestudios.com/sbnet/?p=489