Worth going to ATP for cadet program?

Recently applied to the cadet program have completed the recorded interview so far and was contacted by an ATP admissions coordinator regarding the next steps. I know for the current cadet program you must attend ATP for your training but have heard horror stories about them so was just wondering what the general consensus is if it’s worth it to go to ATP to be accepted to the cadet program. Also does anyone know if you’re required to only instruct at ATP while building to 1500 hours or is it possible instruct at another flight school while in the cadet program?