The airport is very clean.I have only visited this airport just twice inmy life when I travelled from Mumbai to Delhi. The airport is quite spacious. Even though lot of crowd comes in and go still it is so big that you do not feel crowded. The check in counters are enough.Goes without saying that this is one of the most massive, busy and spacious airport in the world. The airport is grandeur and extremely well maintained. Also, fortunately it is well connected through metro which takes you directly to the terminal. .My favourite airport in india.