The Asiana business class lounges in the main and satellite terminals have fairly similar offerings. Decent F&B offerings (including hot selections) with a dedicated dining area and ample seating.

I've visited both recently, and the main difference to me is that the lounge in the main terminal has tarmac views, whereas the one in the satellite terminal does not.

The satellite lounge also feels more spacious.

Some pictures and reviews (From the SQTalk site) below.

Pictures of Asiana Business Class Lounge in ICN Main Terminal (From SQTalk forum)

Pictures of Asiana Business Class Lounge in ICN Satellite Terminal (From SQTalk forum)