I did my PPL there 4 years ago and they were fine. However, there is currently a thread about them in the spanish forum, I don't know if you speak spanish but below is a fairly typical quote of the sentiments....
Buenas,
Lo mismo te digo compañero, es muy triste pero te recomiendo q no vayas a AEM, yo fui alumno e instructor ahí durante 3 años y te aseguro que ya no es lo que era...por calidad y seguridad de que no se vayan a pique vete a otra escuela.
Saludos
Roughly translated the guy is saying that he was a student and then an instructor there for three years and he assures you that the school is not what it was... for quality and safety. Go to another school.
Now, the thread could be by someone with an axe to grind, but there isn't one comment defending them at the moment...