Stevia is wonderful, just get pure extract that doesn'thave fillers. Like shortstuff said it can be bitter if you use too much. The trick is to get the exact amount for your tastes. right before the bitter stage there is also an over powering sweet stage.

I use the pure powder extract because so far it's been the easiest to control and best tasting. Only a few granuals are needed for coffee or tea, so a small bottle used on a daily basis has lasted me for months so far and isn't even half gone. 1/3 tsp = 1 cup of sugar