Sathvik, on CC, many people will tell you negative things about IIT. The reason for this is the fact that it is not ranked very highly in the US News and World Rankings when it comes to Engineering. I want to say it is either in the 50s or 70s, but I can't remember which it is. These people who comment typically know nothing about the professors, nothing about the campus, nothing about the students, and nothing about the coursework. All that they see are numbers that correspond to rankings. Why is IIT not ranked as highly as other schools? There are a few reasons:
1) IIT is not all that well known. Rankings, at least for US News, is all about peer reviews. Well, if not enough people know about the college, it certainly won't get as many reviews by other professors. It is a small, private college, that has more or less laid low.
2) Since IIT is small and not as well known, it does not get nearly as much money in endowments. Whether people want to admit it or not, a large part of the rankings have to do with money that the school has. Money typically brings fame and therefore the "top-notch" schools will be more well known and get better peer reviews.
So those are the main points to consider. Is IIT a top-notch engineering school? Yes, it is considered very highly in engineering and in the students it produces. A payscale study actually put IIT near the top of colleges whose students make the most money upon graduation. As a student of IIT and as a friend to many students at other colleges that are considered "top-ranked engineering schools", I can tell you that the education you get at IIT will be nearly the same quality as that at big name schools like UIUC, Purdue, Wisconsin, Michigan, etc.
As for the Aerospace Program, I have a few friends who are in this program. By what I have gathered, it is a well-done program and will give you the knowledge you need. Many people will get a double major also with Mechanical and Aerospace Engineering because they are so related.
My advice overall is to talk to current students at IIT either by visiting the school or finding reviews online from actual IIT students. The people on CC can tell you all they want about the University, but bottom line is that they know little about the actual quality of the education.