I just upgraded to ReSharper 5.1.1 and it feels like a downgrade. There are many spurious warnings that 5.1 did not include. The most noticeable stems from the use of the Unity IOC container. If I declare an interface, implement the interface on a class, and then do the following:
ReSharper claims that "Class 'Foo' is never instantiated" when it clearly is. I've noticed a number of other problems with bad warnings about stuff not being used when it CLEARLY is (example: if I use two way data binding in XAML to an IOC injected implementation of a view-model, I'm seeing a lot of setter is never used and can be made private -- clearly it's used because it participates in two way data binding!).
I'm off to go downgrade to R# 5.1. :(