ddartt

Not sure if that's the right forum but I thought I'd share my recent (as in, yesterday) experience of connecting in the US. This is probably the most complicated connection I've ever had.
I'm flying on a RTW *A business class ticket, visiting bunch of countries in Asia and then in Central/South America - I'm on a 3 months sabbatical leave. I have Irish and Russian passports, and I use them interchangeably in different countries depending on which one works better for a particular country. I currently live in Zurich. As many know, the price of RTW ticket varies greatly depending on the beginning city. So in and around Europe, and to suit my itinerary, Istanbul was by far the cheapest - over $3k savings compared to starting in Zurich. So I took a cheap positioning flight to get there, and started my journey in Istanbul. No issues whatsoever while visiting many countries in Asia, and then my itinerary was NRT - CUN via IAH (NH for the first leg, UA for the second). I merely had 3 hours connection in IAH.
As I was trying to check in online for the NRT-IAH flight, the check in failed, which is usually not a good sign. Upon arriving to check in desk in NRT, the check in guy looked a bit concerned and finally gave me a phone to speak to someone. The person said he works for the US government and since my ESTA was issued quite a while ago and my itinerary is somewhat complicated, he needs to ask me few questions. So we want through itinerary, why I'm going to those places, where I work, what I do, etc. All in all, 15 mins or so polite chat - he warned me though I'll likely have more questions in IAH because of IST starting point of my trip.
2 boarding passes were printed - NRT to IAH with SSSS, and IAH to CUN without SSSS. Of course, SSSS on the first one meant some secondary security before boarding the NH flight - but they were cool about it, paging me before the boarding started so all good.
Naturally after arriving to IAH I first went to the kiosks as the returning ESTA, the kiosk failed to clear me. So i had to go to passport control desk, who called another guy, who escorted me to that room for further screening. There I had to wait another 20-30 mins, answer pretty much the same questions as in Tokyo which took another 15 mins (he also casually asked if I went to Syria), and was stamped in.
OK cool, then IAH spit me out into arrival hall, where I have to go through security with all departing passengers (the quick passthrough security for connecting flights was closed). After security, I go to the UA club lounge for a quick beer, where the lounge agent reprints my boarding pass to CUN and this one has SSSS on that too. But I'm already past security! The lounge is bad, so I head to the gate, and as we start boarding, my BP fails to scan. Quick chat between GAs and they tell me to just board and they'll sort it out. Well it turns out they couldn't - few mins later the GA comes onboard and asks me to go with her - just as I settle comfortably in my seat and was about to get some pre-flight prosecco. We rush back to security. On the way, she mentions again about the whole Istanbul ticket thingy - at this point, I'm very tired, annoyed, sleepy, pissed off really and have hard time keeping calm and not loosing it. At the security they leisury do their SSSS thing despite my flight is actually about to close. They also do it much more throughout than in Tokyo as in really throwing everything out of my backpack on their table. At this point again I have a hard time keeping calm as I'm super-annoyed. Now the backpack is quite tightly packed, so it takes me a bit of time to re-pack it (even the TSA lady sort of felt sorry and offered to help), then we rush back to the gate and just make the flight. I got my prosecco and big smile as we finally took off.

So some learnings for me:
1) That was totally unexpected. Until your man in Tokyo mentioned the Istanbul thingy, it didn't even cross my mind that this is the reason for all of those issues. Since it was specifically mentioned by the US immigration guy and then even later by the UA staff when walking to security, I feel like it was really the source of all issues.
2) Its unlikely to do with my 2 passports - I've traveled to the US few times before on Irish passport/ESTA and never had an issue.
3) It was particularly annoying as I didn't even need to be in the US. I realize the US do not have a proper transit procedure, but OK what if you deny me entry, are you going to send me away - where? Closest is Mexico and that's exactly where I am actually heading anyway.
4) It wouldn't be half as stressful if not for the last episode of having to leave the aircraft when already boarded, rush to security, etc. Had the IAH-CUN boarding pass printed in NRT have the SSSS already, they'd notice it at IAH security right away. However, before you go through security they actually do scan your boarding pass, why on earth didn't it pop up on their screen at the time? If the lounge agent didn't re-print my boarding pass, would it actually be flagged at all? Why the UA GA didn't page me before boarding if they can see they have SSSS passenger on manifest, just as NH did in NRT? In hindsight though, I should've probably approached the GA myself proactively.
5) I really hope it will not haunt me come ESTA renewal, which is actually fairly soon.

So here we go, be careful with el cheapo ex-IST tickets :-) I'll probably try to avoid connection in the US unless really necessary, I feel like Canada would be so much easier.