Sugar / Sweetened water : To be added or no when blending?

It is depends , but for me, better not to put.

My justifications :

1   ) Somewhat it might be ruined / spoiled the original taste.

2   ) Afraid of imperfect sugar blending residue

3   ) A good ice blended powder / smoothies concentrations has been produced with adequate portions of          sugar

4   ) Too sweet might lead to less satisfy of tasting