I just checked out Sketch. I suppose I should give it the benefit of the doubt but ...
First thing I did was change a font on the intro doc. 2 other places changed (that was the point). Then picked Undo. It only undid my change, not the 2 others that it auto applied.
Next thing I did was open the iOS Icon template. I made a circle, set it to gradient fill, dragged the handle of the fill direction, got residual garbage all over.
Not a good first impression. Should I be more forgiving?