By my personal experience I think allen is a good institute for iitjee and medical preperation.allen provides you with best faculty and materials in india.the teachers are totally devoted toh the students , you come with any doubt they will clear your doubts anytime even on phone.the time table is set in such a way that u can get time for self study. It also provides doubt clearing sessions and extra classes.if you are not able to study at you ur room then you can stay at allen buliding and study.
It provides you with enough space.but at last I want to say that it totally depends on how u grab things and make use of facilities provided . so I think its a good institue overall
