Yes embibe has some good resources, but not useful ones.
Many mistakes, misprints in the material..... Moreover the BITSAT and JEE M test are of much higher level than what will ever come in the exam. Only useful for past year papers and analysis.
JEE ADV material has many things which have only a remote chance in actual adv.
You needed embiums for unlocking things and they are very hard to earn. If you have it unlocked then it's good, otherwise... (Though I tried macro scripts to automate my questions to unlock analysis and all, I recommend 'Pulover's Macro Creator', has a good gui, no need for code )