"The average life of the ordinary citizen ... in Hitler's Germany, was an improvement over the past."
I don't believe that is true for the wage earners. There were longer hours, less wages, resoures were redirected from the production of consumer goods to armaments. Tens of thousands were prosecuted for breaching labour discipline, and thousands executed - all of which added to a climate of terror in the workplace. Also, notwithstanding the ideological commitment to the peasants, they were pretty much abolished as a class. There was obviously some glamour to the military victories of 1939-40, but in material terms they presaged a return of the austerity policies of 1933-35. An improvement over the past? Not over the boom years of '23-'25, and frustrating as the inflation was, it was those with a lot of savings that really suffered more than wage earners.
As to the material advantages of Stalin's Russia, I think they would be pretty hard to justify, as opposed maybe to the post-Stalin era. Stalin's rule involved some brutal industrialisation, wartime austerity, a famine and the liquidation of the kulaks, which were all pretty grim.