hi,
in cell commenting would really enhance this product and really is a must have when managing large sheets. ultimately the row comment button could be the aggregation of all of the rows specific cell comments.
if you take this step and i hope you do, you might want to consider multi cell comment grouping. so, CTRL-clicking say 3 completely unrelated cells ( to select them ) and add a single comment to the 3 cells. hovering over any one of the 3 cells would highlight all 3 (turn brighter or change color), something that not only shows the snippet of comment, but brightens all cells tied to the same comment. not even excel has this one.
thanks for your consideration.