i like your article. good and pragmatic while still keeping clean separation in mind.<p>IMHO the business logic mixing in with persistence or other areas such as the model can and should be improved from all the code i have seen over my career.<p>I favor MVVM in general. i tend to attempt to move as much of the business logic into subclasses of my VMs. that way the VMs are pretty slim and the business rules are all in the one spot.