These impressive figures are probably not due to the quality of the website but due to the monopoly that it enjoys. Like many, I've endured the slow-loading pages but since the last few months I'm happy to have discovered alternatives to IRCTC.
Since a couple of years, IRCTC has started providing an API at a hefty fee for third-party vendors. As a result, there are now a bunch of websites now that offer a superior interface & experience for buying train tickets online at a slightly higher cost, like -
I've tried the first two & am impressed with the clean interface & relative speed with which you can book tickets.
The MakeMyTrip site interface (click to enlarge)
Booking a Tatkal ticket on Cleartrip appeared faster although it still probably hits IRCTC's servers. Some of these sites also occasionally have special offers. For instance, Cleartrip is giving away a cash back of upto Rs.100 on train bookings done through Net Banking till May 31st, 2010.
Also see:
Travel Planning & Reservation Tips using Online Tools