A lot of people don't realize that sugar does a lot more than just sweeten. That's why when you simply replace sugar with a sweetener such as Splenda, your recipe doesn't work the same way.
If you like to bake low-carb, low-sugar recipes you need something that:
Sugar contributes immensely to density. So you also need something that's dense. not/Sugar contributes to that sense of density.
not/Sugar is not a sweetener itself, so you can use Splenda or a similar product to provide the sweetness of sugar. But you need not/Sugar thickener to provide the texture.
You use very little not/Sugar thickener to get the right texture and thickness. For example, most people find low-carb pancake syrup to be too watery. It's not satisfying because it doesn't flow the same, and doesn't feel the same in your mouth. With just a little not/Sugar, you can have low-carb syrup that gives you the mouthfeel, smoothness and thickness that you expect.
A basic example: classic meringue is egg whites and sugar. If you make a meringue with artificial sweetener - it's going to come out like sawdust! Take out sugar's density and texture and what you've got left is flavored dried eggwhites... Meringue needs something to hold the moisture and the bulk of sugar usually does that.
We've formulated not/Sugar thickener to replace the texture of sugar, so your recipes work much like real sugar would. Your low-carb, low sugar baking and cooking results will be better looking and tasting.