Never had any major problems with the site that haven't occured with other airline sites or other internet shopping sites. Find it just as fast as other airlines and it has some features that I like that others don't have.

My worst case was on AA.com. The programmers there were so slack that they didn't do any user requirement analysis outside the four walls of the US. I spent hours trying to make a booking but it wouldn't accept my telephone number.

After talking to 6 different people I finally got a response back a day later that I had to enter my number in a way alien to standard practice this side of the pond. All for the sake of 1000 bonus miles for booking online.