Having just graduated from this department, I would rate Aerospace Dept. as one of the finest in the country.
The curriculum offered here is such that one can easily pursue any of the sub-fields of his/her interest. First few semesters give basic knowledge about Structures, Fluids and Propulsion. There are electives offered in each sub-field in later semesters so that one can dive in for in-depth knowledge. The state-of-the-art facilities (wind tunnels/supercomputing facilities) provide for easy experimenting.
The professors are adept at carrying out research and teaching. This is mostly because 80% of them are IIT alumni-US PhD. So they have a very good understanding of how IITians should be taught. Having gone through similar experiences, they are always willing to help out. This is a huge advantage.
In summary, it is a great dept. to spend your 4 years. Hope this helps.