Originally Posted by
graraps
As long as your flight is on time, the MCT (35 mins?) is more than adequate.
Yesterday (arrival from A departure from C) it took me less than 20 minutes to get out of the plane, go down the steps, enter the bus, be driven to bus gate, go upstairs from bus gate to terminal, visit transfer desk (and wait for previous passenger to be served), walk across to other terminal, clear security (no separate passport control done) and go to the lounge 2 floors up. Lounge was 4 minutes from gate (if you didn't go to the lounge, the gate was 2 minutes from security).
Graraps - It looks like your arriving flight originated from a Schengen destination - that is why you have busses - you arrived at a non-Schengen gate.
When a Schengen flights arrive at a non-Schengen gate (A or B) you are bused around. If that happens they bus you to the bus arrival point for Schengen flights in Terminal C, and before going on to another Schengen (or even non-Schengen) destination you don't need a passport check (they will do a security check).
But were you to arrive with a flight originating from a non-Schengen location there is no escaping the passport check between non-Schengen and Schengen and that is where the queues can evolve. Especially when the KE flight from ICN comes in unloading a huge number of non-European passengers who all are meticulously checked.
I that case it is best just to exit the airport via arrivals hall C and get in again, via regular passport control on landside.
But maybe OP could divulge from where to where he/she is flying - that would probably give the best estimates.