I've seen several people report an unpleasant aftertaste to some artificial sweeteners; stevia in particular (though I think some of that may be ingredients added to make the sweetener "pour like sugar", etc. and some of it may be genetic, like the individuals who find the herb cilantro tastes like soap to them). There also are recent studies indicating that, in diabetics, even some artificial sweeteners promote the same digestive reaction as sugar.

So I've pretty much sworn off artificial sweeteners myself. If a recipe for a roast calls for, say, a tablespoon of brown sugar, and I think it's important to the taste of the dish, I'll put in the brown sugar; my portion of it will have just a smidge of "real" sugar and I don't need to think about what the artificial sweeteners may be doing to the dish or to me. I don't drink diet pop and my only "sweet" is >80% dark chocolate. But I'll say that's by my choice.