QGIS this year split into two branches:
Latest release (now 2.10.2)
Long term release (now 2.8.2)
I am not sure how is it normally in larger companies but I think having (hard)core GIS employees who need to work with OSGeo4W version and GIS users who are fine with standalone version is not that rare. And if these two groups need to work on the same projects they need same versions of QGIS.
That makes the GIS employees need to have either two versions (OSGeo4W 2.10 and standalone 2.8) or possibility to be able to downgrade with OSGeo4W to long term release version.
Is downgrade with OSGeo4W to long term release possible somehow? At this stage I have possibility to only downgrade to 2.10.1 in the advanced installed list.