I have never tried eating a ripe red ginseng berry. I don't think they would be sweet though, not like a grape or blueberry.
I would expect them to be bitter, like the most of the rest of the plant is.
I will have to try one out next year and see.
I have eaten the flower spike (pre-berry set)... and I would caution you that they are very potent. I have read that the flower spike has the highest levels of ginsenosides. Many times higher than the root or stems/leaves.
A tiny bit.. goes a LONG WAY with the flower spike.
I have eaten every other part of the plant too, or at least chewed it up to get the juice out of it (leaves/stems).
I do eat the root, chew it up and eat it. I sometimes eat it plain (dry, in chips or slices) or my favorite the small root hairs.
I also re-hydrate it at times putting it in my coffee or some hot green tea. The slied root softens up nicely that way and is easy to chew up and eat.
My least favorite part of the root is the root neck. I prefer the rest of root, but not so much the root neck. I do eat those too, but it's my last choice.
TNhunter