I've now finished Stalingrad and went straight into Berlin.Starts with a summing up of invading Russia and then gets to Stalingrad. I'd read it in a oner though. I'm getting through it quite quick.
Stalingrad has the quote of a Russian officer saying to a German POW, "see that, (pointing at the ruined Stalingrad) that is how Berlin will look."
Berlin opens with the same and was written two years later.