Just got back from a LAX-DPS round trip on CX J booked on justfly.com There was no problem though I didn't try to make any change or cancellation. Miles for the way out have been already posted to my AAdvantage account as expected.

The site works fine. It is when you need to change/cancel or request anything other than transport from A to B that their service becomes an issue.

Hmmmmm....

Great. They do sell legit tickets, just don't pay them to reserve seats (they won't stick) and expect an obscenely egregious service charge for a refund even if a flight is cancelled due to reasons beyond your control--it's happened to me when flights from IST to the USA were banned in 2016.

Yes, I set my expectations really low (expect pretty much nothing more than original ticketing) when I use an OTA.

I've never booked on justfly, but I've often seen them with the lowest fares on international business class. I've always had good luck booking my itinerary on Priceline and then getting a refund (between $30 and $300) by comparing the price I paid with the lower justfly price using Priceline's "best price guarantee". I've never had an issue getting the refund and obviously having your ticket with Priceline is much better than with justfly. Just figured I'd pass this along because you can get justfly prices without having to deal with their bait-and-switch booking practices, exorbitant fees, and dodgy customer service.