Delta has had problems for years.

Much of the anger over the changes have first come from the NWA people who came over to the DL system. Even before the airlines were merged, the great NW folk in charge of the FF program started sliding nasty stuff into emails.

These semi-hidden changes to the FF program were large, and DL seems to have a consistent record of trying to sneak things by us, or not announcing changes at all.

I've had DL phone representatives lie frequently. Just last year, I booked an Intra-Asia Biz award for 40k by a great Chisholm agent (Former NWA Elite agents). A week later, I called to assign seats, and the non-Chisholm agent claimed that Intra-Asia award had ALWAYS been 70k. Uh, duhhh, I don't think so.

As someone who has ticketed close to 3 million miles in award tickets in the last 4 years, using NW/DL miles, I can attest at how much harder it is to use DL miles. Yes, there are great threads here on FT on how to get low bookings.

I used to be able to use the NW booking engine, and have a trip to South Africa, Argentina, and lots of other places at low levels, in Biz class. Not in 5 hours of trying all combinations, but in just a few minutes, with no agent intervention needed.

I have not bought a normal revenue DL ticket in a long time. Continental, which has much more transparent dealings with its FF community gets much of the flights I do buy each year. They're far from perfect, but at least they seem to be more honest. And their online booking works much better than DL. Lots of partners too!