I am an iitjee 2017 aspirant and a student of fiitjee.
FIiitjee has many teachers who are iitians and other teachers who have a great knowledge and experience.
Many students say that some particular teachers in fiitjee are very bad in teaching.
But in my perception no teacher is bad.
Because everybody has his own learning style and when their style doesnt match with that of the teacher they blame teacher.
I suggest you that if you decide to go to fiitjee or any other coaching classes never find any fault in teacher.
Only one person can assure your success,
and that is you.
If you dont do self study, you would get nothing left in your mind after a few days.
When a teacher teaches in class in fiitjee he cleares all concepts and doubts asked by students.
After that if you dont revise the same at proper intervals of time you would forget all.
The fiitjeestudents who get success in iitjee really do a lot of hard work in self study under the guidance of fiitjee teachers.
Its infrastructure is very good.
No problem of summer and winter since classrooms have ac and fans.
they take tests on every second monday.
and the teachers motivate students a lot.
But still remember that they are giving you the direction, magnitude will be produced by your self study!
goodluck!