I've used them three or four times and it has worked pretty well except for the one time I needed something the web site couldn't provide. Even that all worked out but they weren't very responsive.

They will charge you their own fee if you cancel, on top of the airline's, unless you pay them $20 at time of purchase. I tried that precisely once because it was supposed to give it back as a credit on my next order -- but didn't.

Overall, they really do seem to have the tickets they claim to. Dutch owned, I believe, but they do have at least one US office in the SF bay area.