I've heard that too. I wonder if anyone has tried to just add their own bit of commercial splenda to the actual juice you wanna make sweeter.
I've heard that liquid stevia is what you should use and only 1 or 2 drops per 15ml. Only get pure stevia (sweetleaf I think is the brand) that is sold at like whole foods, it doesn't have alcohol added.
Edit: this comment is directed to casualuser's question of sweeteners to add to ejuice