I haven't had any issues in PHL, JFK, SFO, LAX or ORD just showing them my card and acting like I belong. Then again, those cities probably see more non-UA *G than the others combined. Enjoy the lounge, such as it is. I don't really find them all that useful except for dealing with irregular operations (and food & booze internationally). No food, no drinks and no WiFi takes away most of the utility from me. Then again, I have a stack of drink chits that I've been collecting on my international itineraries where they do give them out, so I have a few trips worth that I can drink for free.