Agreed. With ReSharper, I don't recall a time where syntax was incorrect at compile time. It immediately indicates any syntax errors at coding time.

However, the inline method/function definition that the OP mentions is something I have also wanted. The two closest features are:

1) Visual Studio has a 'Code Definition Window' (http://msdn.microsoft.com/en-us/library/f5yx24a6%28v=VS.100%...) that dynamically displays the contents of a method in a separate window pane. Although it is not inline, at least you can visually see the code without navigating away from the current source file.

2) In ReSharper, you can sort of fake it by calling the command 'Inline Method' and unchecking 'Inline all usages' and then Undo when done inspecting the code. However, that is a hack with its share of problems. I'd prefer a feature to toggle the inline method content in a preview mode without actually modifying any existing code.