I used them a couple times in the late 90's, and found them to be such a pain to deal with that it wasn't worth the hassle.

Example: Called to book fares, charged mine to my credit card, my sister's to hers. They called back a week later to tell me that my sister's card didn't go through, they need a new card, but can't give me the fare as it's expired. 2 hours of arguing with them, I got the fare.

Find out they have now charged my sister twice for the same trip, and getting a refund took 4 months, as they wouldn't admit any wrongdoing, until I got a VP on the phone and caught her in a lie about the whole thing.

Spent too many hours on the phone either on hold or arguing with them, just wasn't worth the money I was "saving"