I was there a week ago. Immigration experience depends on your nationality / passport you hold. Entering into Korea at T2 can be a huge pain for Korean citizens and SES eligible passport holders (ie Hong Kong) because they all use the same queue. For other nationalities, I would say it’s about the same as T1. Departure I think it’s abit better than T1 though.

Here comes the challenge, there is always a big queue for the KE Prestige lounges (Gate 253) given their central location and proximity to immigration exits. Quality of the lounges is way better than OZ but they seriously need to think of ways to tackle the overcrowding issues. When I was queuing for the Gate 253 lounge, the agent asked me in Korean if I would consider using the Matina Lounge which I politely declined.