Right now you can add units to your currently selected group by holding shift and highlighting/clicking on units not in the group. What you can't do however is select a group of units (for example broodmother + spiderlings) that includes your hero and use the shift+F1 combination to REMOVE the hero from the selection.

I think this deselection will be an important part for heroes that are soon to come as well as heroes in the pool presently. A quick way to highlight all of your spiderlingss with brood would be drag mouse over all of your units and press shift+F1. I beleive you can set a keybind to select all non hero units, but this will be a problem when my favorite hero, geomancer, is added. A key way to seperate different meepos is to deselect a meepo with shift+F1-4.

I hope this can be redesigned to resemble the WC3 engine, as I've become accustomed to controling all non hero units by manually removing my hero from a group of all my units with shift+F1.