I believe the experience is very different for different people, depending largely on your own personality and world view. Though there are commonalities that I’ve attempted to sum up in the following points.
Academics:
It’s rigourous. More so than any college I know of. But in no way unmanageable, or a burden that doesn’t let you enjoy your college life. You learn to appreciate the thorough curriculum when you realise how far ahead you actually are compared to your peers.
Research:
No institution that I’ve been to (I’ve been to plenty, IIT B, D, M included) comes close to the quality of research being undertaken in Computer Science at the undergrad level. Period. And if you, like me, end up enjoying research work, this place is love.