Windows 7 64 bit
GeForce GTX 960
Select more/less does'nt work right in Face Select Mode
Add a plane,
got to Edit Mode and subdivide it 32 times,
switch to Edge Select Mode,
select random about 85 % of the mesh.
Then select less one step by hitting CRTL + Minus Num.
Watch the selection and switch to Vertex Select Mode.
There are still some single Vertices selected, wich didn't show up as "selected", if Edge Select Mode was active,
so as if "Select more/less" always works vertex based, no matter what select mode is active.
I recogniced this when I was moving such selection and some obviously not selected single Vertices was moving with the selection nevertheless.
Off course, single Vertices can't be shown up as selected in Edge Select Mode, but they also shouldn't be selected, no matter what.