I have not worked at i2, but I will throw in my 2 cents. I applied over a year ago to i2 and I was refused there despite having over 9 years teaching experience, all the required documents and a passion for the job. The interview I had began with a question about my faith which I duly answered because I like to always sustain clarity in my relations with people, especially people I will be seeing daily.
After discussion, I have been refused the job on the grounds that they did not believe me to be able to juggle between work and my stated goal of learning Chinese saying "You are a good teacher indeed, but the working schedule may not allow you to learn Chinese that well as you wish".
I never thought that having 2 days off in the week, plus the mornings of 3 days off (plus evenings of Saturday and Sunday) would not be enough to learn Chinese...at least as "well as" I wish. Then to their credit, I can understand that in the "money over education" scheme they live by, it is unimaginable that a language may be learned in such a manner.
And yeah...religion had nothing to do with that.
P.S: Finally, local teachers in Kunming teaching in other branches narrated of reviews by actual teachers who worked in i2 saying very similar things the negative reviews here do.