I worked with both ABX and FedEx at LAX. For FE, they have a sweet operation going on. They are very efficient and when problems would arise, they were quick to act on it and solve it. I was quite impressed with FedEx.
Then there's ABX. I would work with ABX in the mornings for their 430am and 515am flights. I can truly say that I have never seen a worse operation than ABX. I think ABX only flies the 767 into LAX, both the -200 and -300 Package Freighters coming from Dayton and Wilmington. The planes were always late, and when they came in, they were in horrid shape. So many times, the flaps would be rusted and the aircraft was filthy. Inside, it smelled like cat urine and if I had a dollar for everytime ABX dropped a package off the belt, stepped on a package, or forgot about a package, then I'd be a rich rich man. Also, the equipment they used was so ancient, that I was suprised it worked. It was just a half-done operation. They were almost as bad as Kitty Hawk, who I'd say is the worst operator anywhere, ever. I'd like to say that this is at LAX, and possibly, ABX's ops are better elsewhere. But from my firsthand experience with them, it was an astonishing sight.
Some people may say that this is how all cargo airlines are at one point, but FedEx would never do anything like that. And if they did, they'd be fired. Also Polar Air and UPS were very good.
LAX also has BAX fly in. They were up there with ABX in terms of ops. Their DC-8s from 1965 were grossly outdated. The cockpit had wires exposed the plane always looked like this was its last flight. The only reason I don't rank BAX with ABX and Kitty Hawk is because I didn't have as much experience with them, and I don't want to say anything I don't know for sure.
My posts/replies are strictly my opinion and not that of any company, organization, or Southwest Airlines.