I have been using IRCTC since 2012. It is one of the best websites that are made accirding to necessity of users. Since 2012, it has evolved so much. It is a pure digital website which is cashless and paperless, long before Digital India program.
Earlier this website was slow. During tatkal booking it was about to impossible to book tickets. But the present scenario is such, ticket can be booked any time any place. Almost every train traveller in India are now booking their train tickets from IRCTC
In addition to train tickets, there are many more things which are present in IRCTC such as flight booking, hotels of railways, foods etc. So overall its a very nice website designed as for the easiness of users