I used Sucralose for my shakes a while back when i was using my own flavouring, its not too bad and better than me drinking down aspartame. I have not tried Stevia but i'll don't add sweetener to anything I only have it when I drink some soft drink. Also just because Stevia is natural does not mean it is safe, it has not been proven yet same could be said for aspartame not being bad for you though. Give us all 30 years when we start getting huge increases in cancer then we will have real proof.