I think there are more differences between v40 and v45, all the way from the architecture to implemented patterns and coding best practices
The Design Pattern Framework 4.5 seems simpler, cleaner, but at the same time lacks samples that v4 had, such as DTOs in BL, Security Tokens, Adapter Pattern in DL, General Log functionality, Encryption, Image services, Hosting layer, and more
With the inclusion of the Web Api, and removing WCF the developers decided to go for simplistic sample vs detail sample. That and the fact that the Web Api is new and certain things are not well defined yet.
So I am continuously going back to v4 for some references not existing in v45