I absolutely love the transition from before prison in 1945 to when you come out in the early 1950's post-war. It's actually one of the most smartest and immersive inclusions I've ever seen in a game and some things aren't even noticeable. In the 40's it's snowy, the cars are old, the music is slow, the shops are barren and the vibe in the city is quiet. Coming out and there's no snow, the war is over, cars are more flashy, new shops, billboards are updated, new buildings, people are dressed differently, the music is new and funky and the city is much more lively. It's really well done.
Mafia 2 takes around 11-13 hours usually which is a bit of a shame. It's amazing in that time but 5 more chapters would have been welcome and the latter stages do feel a bit rushed.