Anybody has experience with cooking with stevia?

I’m e.g. interested in taste, amounts, whether to get it fresh/ground/?, where to get it (do they have it at AH or EcoPlaza?), and what to use for bulk replacement.

I wanna try and make sugar free brownies and lemonade tonight, and am thinking of using beets and/or bananas together with stevia for the brownies and just stevia for lemonade.