A few notes about my Terminal 2 to Terminal 3 transfer experience in Beijing (PEK). I was typing these notes as events were unfolding so I apologize for the somewhat unorganized nature of this "report."

Prior to getting to the airport in Pusan, I called both Korean Air and United, and both airlines confirmed that my bags will be interlined all the way through to Chicago. In Pusan, Korean Air issued my boarding passes for both PUS-PEK and PEK-ORD flights, and again assured me that my bags would be checked-in all the way through to Chicago (i.e., no need to pick them up in Terminal 2 and then re-check with United in Terminal 3 in Beijing).

As a side note, in PUS, I was not allowed to access Asiana's lounge (despite my *G status and a same-day Star Alliance boarding pass). I have no status with Korean Air, but I did get access to their lounge in PUS based on the purchased cabin. In any case, after experiencing both within the past few months, I have to say that Asiana's Pusan lounge is nicer and also better stocked, but the difference is not meaningful.

My flight from Pusan departed roughly on time (door closed at 7:55 am, pushed off the gate at 8:02 am; took off at 8:09 am) and landed in Beijing at 9:05 am. It took another 15 minutes to get to the gate and get the door open (luckily, no bus-from-plane-to-terminal transfer this time). (As usual, they did not have "blue" forms on the plane, only "yellow" forms, which made me think that I should stock up on a few of these in PEK for future transfers in China.) I was one of the first people to leave the plane, boarding passes and the e-ticket print out in hand, pacing to find that one presumably not very well marked place that would issue me my 24 hour transit stamp. Turns out that right at the end of the gate bridge there was a person wearing Air China tags holding UA850 signage...

The person rushed me to the International Transfer Service Counter that actually wasn't all that hard to find (I was there by 9:25 am, with one more person being helped at the desk, but two available attendands). At the desk, they seemed mostly concerned with my luggage tags. I stood there not really knowing what was going on for 30 minutes. There was literally no one else besides the two of us. The whole section of the terminal seemed dead. The desk is co-operated by Air China (handling Korean Air, Aeroflot, Air Koryo, IranAir, SaipanAir, Veietnam Airlines, AZAL, Jeju Air, PIA, Vladivostok Air, Garuda Indonesia, Swift Air, and American) and Beijing Aviation Ground Services Co. Ltd. (handling British Airways, Cathay Pacific, Air France, ST Airlines, Singapore Airlines, Hongkong Airlines, Hainan Airlines, Emirates, SriLankan, Philippines Airlines, Etihad, Delta, JAL, Air Astana, and El Al Isreal).

The other person was also trying to get to UA850 and was at the desk for an hour already by the time I showed up (allegedly), but did not have his United boarding pass, so they were trying to figure out how to get him one in Terminal 2. At around 9:55 am he became somewhat aggressive, swearing and taking pictures of everyone. Around that time, the desk people wrote out his boarding pass by hand on an empty Air China boarding pass stock and at 10:00 am, they decided that we won't be filling out any forms or getting any stamps but instead will get to use the airside transfer service. I still had to go through an empty but staffed side immigration area and a very strict security screening (I had to take out my spare contact lenses from the bag...). By 10:10 am we were on the airside bus from Terminal 2 directly to Terminal 3-E, by 10:22 am I was at T3-E, off the elevator, right under the T3-E first class lounge. I was at the lounge at 10:25 am. (Certainly not my favorite airline lounge in Asia, but works just fine. When I got to the lounge there was pretty much no food because breakfast ends at 10:30 and there is a break before lunch service...)

The PEK-ORD flight was on time, with boarding scheduled for 11:15 am.

The bottom line is that I was committed and at least somewhat prepared to make the "standard" Terminal 2 to Terminal 3 transfer, and with enough luck on my side, maybe I would actually be able to make it, but I never had to.

I used to connect in Beijing to Asiana flights, which are also in Terminal 3, but after schedule changes, only Korean Air flights work for me for same day connections. Similar story for connecting to Pusan through Shanghai. I can technically fly to Incheon directly from Chicago on Asiana, but that flight lands at 4 am and the connecting flights to Pusan are from Gimpo, which is a much longer ride than the Terminal 2 to Terminal 3 shuttle ride in Beijing (and taking KTX with checked-in luggage is also not ideal).

Thanks everyone for your helpful comments!