Deep Red is a cinematic tour-de-force, IMO more so than Suspiria, but it is still to an extent confined within the constraints of narrative-based film. For me, Inferno is the Argento film that represents 'total film' in its truest sense - even though it isn't perfect - Deep Red (again IMO moreso than the much more lauded Suspiria) does however come very close.
Suffice to say in all plaudits to Argento though that the chronological triumvarate of Deep Red, Suspiria and Inferno absolutely delineates his cinematic epoch. Tenebrae is again in a class of its own; just not this particular one.