Welcome to my world!! I am a US1 (chairman's preferred) and have noticed a lot of 1K's sitting in first class with me now. I recently flew UA from PIT to DFW via ORD and was pleasantly shocked at the upgrades I received on UA. The PIT UA agents have always been nice to me and upgraded me or seated me in E+ even before the codeshare. And Jan in the RCC in DFW was nice and gave me a better seat in E+ since the agent that I initially encountered kept me stuck in the middle seat in the last row. Thanks Jan!!
Now if only US would create an E+ section. But I don't want to loose a row of first class. I like having 3 rows or more. Unlike UA.