I don't find the AS goofy, but I would still carry the P99AS de-cocked. The double-action mode is an extra and unobtrusive margin of safety. The P99AS still has a quite good trigger in double-action mode, and I find the transition to single-action negligible.
As I see it, the Anti-Stress mode is just that - a mode for use in stressful situation. Say you are quickly loading and chambering a round in an emergency (say a home invasion during the night) and neglect to de-cock from single action mode (and the P99AS has a rather light and short single-action trigger). The Anti-Stress trigger adds a measure of safety to help keep something bad from happening. You will still have a very light, crisp trigger, but the trigger travel is increased. Of course, there is the contingent that swears they can keep their "booger hooker" off the trigger at all times, but in extremely stressful conditions can test even the best-trained and introduce surprises no one expects. As always, YMMV.
This is why I still feel the P99AS is still one of the best options for a home defense pistol. The AS trigger is very well thought-out, and I'm surprised more pistols (aside from various P99 clones/copies like the MR9/SW99/TP9) haven't made use of it.