@Miksha, I reside near Ateneo and plan to send my sons there (although 50% convinced pa lang ako since I am also considering a Montessori or a progressive school within the area). From what I understand based on testimonials of friends of mine who send their sons there, here's the feedback:
1. curriculum and the academic performance of students
Traditional curriculum, heavy on homework
Not sure what you mean about academic performance of students - is it vs. students from other schools? In which subjects?
Ateneo is traditionally strong in the liberal arts, history and philosophy so I guess strong ang grade school sa Reading, Languages, History and Social Studies. Plus factor for me ang Christian Living/Religion classes since I am a traditional Catholic - I do believe in Ignatian spirituality. Eto ang absent sa progressive at Montessori schools.
2. Student environment.
The Ateneo campus is unparalleled when it comes to beauty (I so love the trees there), space (it is very spacious), venues for different sports - they have a football field, baseball field, tennis courts, basketball courts, etc. and in fact, eto ang isang gustong-gusto ko about the campus- and proximity to tutorial centers and after-school activities (art, music and enrichment centers are all accessible via Katipunan Avenue).
Re students, there are bullies as you would expect from 40+ students per class. I hate to say it, but if you are talking about such numbers, for sure may mga batang hindi masyadong okay. This is one of my concerns actually. Our neighbors pulled out their sons because of bullying.

3. Student-teacher ratio.Teacher feedback, teacher-student relaitionship
42-45 students per section, around 14 sections yata per grade level
May parent-teacher conferences sila, 1 per quarter yata.
I do not know how it is now, but most of my friends who came from Ateneo have fond memories of their teachers .
4. School stability
Very stable naman siguro ang institution na ito, kasi 150 years na in the Philippines.

5. Tuition Fee
This year, for prep, almost 100k.
6. Any plus factors (aironditioned rooms, shuttle service, etc...)
The rooms are not air conditioned. There are shuttle services depending on the area where you live.
I will ask my fellow parents sa preschool ng kids ko what they think of Ateneo. Several of the students who "graduate" from my sons' preschool go to Ateneo for prep kasi.
