It's pretty simple. Direct drive is weak, so if you make enough power to overcome the drag, then you are in danger of breaking parts every time it shifts. Raising shift points with valve body mods and governer changes can help, but it comes back to the same thing.
If your car is pretty stock then a tight non-locking converter drives 100% better than the DD unit, you just won't have a high stall. If you run the non locker with 3.73 gears, then you won't really miss the higher stall. Win all around as gas mileage won't really suffer noticeably and the car will be quicker.
If your car is a long ways from stock and you want to go fast, a high stall DD sounds like a good idea until you consider that a hard 2-3 shift can and will tend to shear off the small input shaft, hardened or otherwise. Some people have had success with this but it's sketchy at best. It also means you have to run a weak converter which is subject to ballooning at high rpm which won't necessarily show it's ugly face until you loose engine bearings or the converter starts to loose efficiency due to case distortion.
I have said differently in the past, mostly because I was relying on other people's statements rather than speaking from experience but as my experience with AOD's has increased (much to my chagrin), my appreciation for the DD converter has diminished significantly.
Now a properly locking converter (triple disk clutch type) is significantly superior to an open converter. Problem is you have to run a modern transmission to use this, of which the AOD is not.