I just visited the OZ lounge at ICN yesterday for the first time and can confirm most of the opinions expressed here:

1. F&B offerings are poor - the worst compared to all the home lounges in Asia of other Asian airlines, e.g. CX, SQ, BR, NH, TG, MH, etc. In fact, it's worse than even many other US & European airlines' lounges.

2. Massage chairs are nice. When I was there, it wasn't crowded, and 3 out of around 6 (?) were free.

3. Shower rooms are nice - no personal toiletry items, just big bottles of Dove shampoo, conditioner and shower gel, and other local-branded hair gel, lotion, etc.

4. Not possible to lounge hop for *G - OZ is the only airline lounge there, and the SQ lounge is in a different concourse (that you can get to but not return from, according to the information booth lady). There are, however, a couple of private lounges for people with certain credit cards and/or membership.