I've sat next to two UGS, one SNA-ORD in "F" and one LAX-LHR in "Y" (17A, B). Both were extremely nice folks. The one in SNA-ORD got ALOT of attention - somebody from the airport came up and chatted with him for a good 20 minutes, discussing all kinds of stuff. He was apparently VERY important to UA, but he wasn't a jerk at all and I appreciated that.