I had to re-check my bag but that's only because I booked my tickets separately. Original flight was ICN-SFO round trip. The airport quality is great although you can get lost because it's big and Korean staff are not too pleasant. I was trying to find Korean Air customer service inside the terminal and followed some signs then ended up in an area which had some staff training going on. They rudely told me I was in the wrong place when and just told me to walk up the escalater and go far west.

The parts I liked where the VR demo section, free showers, a quiet, relaxing area for naps and free tours for long layovers. I found three paid lounges from $25 USD to $60 which included good wifi, beer, and food. I stayed at the one for $25. Food was great, it didn't appear any worse then the other lounges. It was actually more quiet with less people possibly because it's near the end.