@ Seth -- My understanding is that they're not processing award ticket upgrades due to "limitations," but at the same time won't be upgrading at the gate, even with empty seats. I might be wrong, and as always, the gate agent has quite a bit of power in this case.
@ Sam -- Sure, every airline can advertise they're the best, and if you've read my blog for a long time you'll know I've "called out" virtually every airline once or twice. Sorry, this is just dirty. Most airlines make "dirty" moves once in a while, and I'll call them out too.
SkyMiles isn't a bad program, especially if you don't earn miles through flying. If I just earned miles through flying, I'd feel cheated, given that I can earn more miles with very little effort through partner activity when they have promotions. And it's not true that they don't block partner award inventory. They have widespread and consistent blocking, actually. Look at Air France first class and Korean Air first class. In my book that's just about as bad as Starnet blocking, but at least they're straightforward about it.
Don't get me wrong, Delta is a pretty good airline to fly on, but most would agree they have the weakest mileage program of the legacies. And there's a reason for that. Just because they use marketing terms like "best in class" doesn't make it so.