My experience 2 weeks ago:
Site did not work with any of my US-issued or Canadian credit cards. It got to the Mastercard SecureCode stage for one of my Canadian cards, but still failed. I got it to work with my Hong Kong issued HSBC Mastercard once I passed the Securecode check.
Aside from that piece of frustration, I found the site adequate to use and book my train ticket. I ended up not even having to show my ticket on board, the conductor already had my name down and just checked my passport.