The windows forms designer and code generated by it still lacks some features which can be a real PITA if you're bitten by them:
- Designer: Allow controls implemented by generic classes.
- Designer: Allow controls with an abstract base class.
- "find all references" and refactorings do not honor designer-generated DataBindings which bind to objects or types. This allows e. G. rename-refactoring to break databindings without notice.