Hi all.
A couple of minutes in Rhino 8 and… 
2 SubD open cylinders.
Window Sub-select like this:
… on Rhino 7 you can then CTRL-click to remove from selection all sub-elements of either of the 2 SubD tubes.
On Rhino 8 you can’t.
(DON’T give me alternatives for this extremely trivial example, please…)
For whatever reason this perfectly working workflow was removed… I don’t care.
Bring it back! 
Why should we lose controls with an upgrade? wtf…
On packed situations with many overlapping complex geometries, I can do a CTRL-SHIFT + window selection over an area of the screen, for example i get:
75 SubD edges, 54 SubD vertices, 24 SubD faces, 651 edges, 167 surfaces, 428 vertices, 3853 mesh edges, 1841 mesh vertices, 2013 mesh faces added to selection.
Then, with 2 simple CTRL-click (half second?) I can remove:
1 closed mesh removed from selection.
1 open polysurface removed from selection.
I am left with just the SubD elements, where i can then transform/delete/edit them easily.
On Rhino 8 I would need to first hide geometries or change the filter (but filter is not enough if same-type geometries) back and forth every time I do this.
No way! Easier to stay on 7. But this is the opposite of solving a problem.