Grouping option - show no rows if no details are shown

Another one for the wishlist: with grouping you can easily make an overview of underlaying number of records, or show the subgroups, etc. When hiding a lot of columns this could be an easy way to make a comprehensive view of the table. It turns out that even if you hide columns, a (blank) row is still displayed for every row in the table. That kind of kills the idea of getting a compact view.
So my wish is for an option to not show (a blank) row for each row in the table.
This is what I am getting now:


This is what I would like to see:
image
This is the original ungrouped view: