Zax2 - probably too late for a response but I worked there for two years. Many of the teachers had been with EF Inst for 5+ years but know that it is NOT an affiliate of the "EF" worldwide franchise but a former member that just ripped the name and changed it enough that EF can't (or doesn't care enough to) stop it.
Those who teach at the branches seem generally happy - those who teach at the contract University location are no so. The University students are very unmotivated and difficult to work with but are nice kids in general. There is almost no one left that taught there the first two years... all have moved on. Four weeks into the 1st semester last year the program lost about 1/3 of the students (long story) and rather that lay anyone off, they cut everyones salary in half and had us work 60% of the time - right, the math doesn't work.
Prior to this the company was considered as one of the best in Istanbul to work at but they had trouble paying salaries on time last year.
Hope this helps but you are probably somewhere else by now.
Sincerely, Rich