Necessity of Coaching for IPCC


I had joined a coaching centre for my IPCC(both groups,may 2011 attempt) I am not at all satisfied there(nearly 600 members in a hall,suffocating, and much time waste,nearly 1 hr while entering and exiting,the coaching timing are 6 am to 6pm,the teaching was very slow and average) and i so I stopped attending temporarily(one week passed by). I am reffering to books and i am able to understand all the topics very clearly. But I feel tensed that I am taking risk. I managed to score 158/200 in my cpt(june 2010 attempt) with 2months preperation(Science background and own preperation. I am prescribing  that because may be any estimation could be done on me).could any one suggest me whether i am doing right?