I have used the IRCTC site a couple of times for online reservation of train tickets. The service is pretty good.
The design of the actual reservation site(https://indianrail.gov.in) is good. But the reservation enquiry site(https://indianrail.gov.in/) is not user friendly at all. One has to really go back and forth to get the links that give the details like station codes, train numbers, train schedules, etc.
Considering the volume of transactions, this site is pretty good on the speed aspect. As one can understand, even bank sites like ICICI take similar amount of time to complete the transactions.
Also, the Train Ticket Inspectors happily accept the e-ticket print outs without making any fuss. Sometimes, they don’t even bother asking the passenger the identify proof that is supposed to be produced with the e-ticket.
Pros:
One can avoid the long queues at the reservation counters. It saves a lot of time and energy.
The site is user friendly and informative and up to date.
Cons:
1.8% of the total cost of tickets added by banks as service charge irrespective of the mode of payment. This is applicable for credit cards, debit cards and also for the direct debit facility provided by some banks. Ofcourse, this is the price that we need to pay to avail the services.