Now coming to the question, How good it is?
It depends on whom you are comparing with, see offline institutions have an edge over online institute because you have to follow a more strict routine there but since online institutions had to provide recorded lecture so there will be times when you feel lazy and skip lectures hoping to cover in recorded lectures.
But I guess during this lockdown period we don’t have the luxury of offline institutions so let’s compare it only with other online platforms. See the best thing about Unacademy is they provide you option with which teacher you want to study? My sister enrolled in Allen batch and a friend of her took DLP from Allen because she wanted to study with some particular teachers but after some time those teachers from Allen joined Unacademy and my sister was taking the benefit despite paying so much less than her friend.
Although there are various other sources where you can study for free and they also provide quality education but in that case you have to be extremely motivated and loyal becuase there is no routine or scheduled tests. So it is very easy for a student to be distracted. That’s the advantage of Unacademy over free YouTube videos and of offline coachings over Unacademy.
So overall Unacademy is a good platform having excellent teachers and more importantly a schedule for you to follow.