I posted in another thread, I landed at 5pm on a Monday. It took me 2 hours to get though immigration. T1 has never taken me more than 30 minutes and usually less than 10-15 min and I've been flying in since icn opened. The foreign passport line was crazy long and there was at most 8 immigration officers. Koreans probably took an hour, it was much faster but still long lines since it's the machines. Unless it was always this mess there, they can't handle the extra volume from Asiana. I hate this new terminal....lol