I only sampled Splenda and haven't really worked with it. (Tried it; hated the taste.)
Whey Low acts just like sugar. I've used it to make toffee (the crunchy Health-bar style stuff), a quickie skillet-fried custard (that looks too ugly to picture online but tastes wonderful), etc. etc. I have several "soft drink" recipes I'll be putting online that are sweetened with a simple syrup made with Whey Low (1.something carb per tablespoon of simple syrup versus 12 carbs per T for sugar).
Whey Low has 1 effective carb per teaspoon. Very low glycemic index number (that I don't recall offhand).
That what you wanted to know? (I have an article about it at http://www.cookingwithpam.com/sugarfree/ and Whey Low has a pretty good FAQ page on their site.)
Yes - that's what I wanted to know! LOL
OK -- looks like I'm gonna have to take the plunge and get some. OH!! One more thing... it doesn't affect you like the sugar alcohols does it?? Ahem....
My husband tried Splenda and he liked it in his coffee, but he now he uses Stevia which is from a plant. No chemicals. I don't know if you can cook with it.