I worked there from 2011 to 2013.
Compared to most schools, it seemed like a wayyyyy better arrangement than most. They definitely work you hard but that's Korean Culture. We used to work from 8:30-6 some days and 8:30-7:30 on others. You get a lunch break (provided) and a prep shifts, sometimes too. We had about 10 foreign teachers when I was there and 4 Korean teaching assistants. There were lots of adorable field trips.
The apartments were large single rooms (I had an actual bedroom - but that was rare). Pay was 2.1million plus 1 month bonus at the end of the contract, and paid flights both ways. I don't think that is still offered.