I'd have to look it up again to certain, but I think you'll find ATi's AA is based on a rotated grid, with the ability to change (jiiter) the sampling points, which is the basis for temporal AA being feasible.
I think you will find that many ordinary people are better acquainted with their video control panel than you give them credit for. They may not always fully understand why a setting has the effect it does, but that doesn't stop them experimenting and knowing the results the like.
Like I said early on, provide sensible defaults by all means, but allow those who want to change things to change them.
The reason OpenGL guy trys to twist my words and argue with me is because most of ATi's optimizations are built into the hardware and cannot be disabled, there is no alternate method. Most of nVidia's optimizations by contrast are driver level and the hardware is capable of traditional operation. So Ati has little choice but to oppose choice, to coverup the fact their hardware operates only in shortcut mode.