This may be too-tall of an order but I really miss the subtle performance differences that Mac Apps have over apps that run on Macs. Just to name a few:
- Movable windows
- Windows that persist unless closed
- Drag and drop
- Contextual menus
- On screen contextual help
- Consistency of point-and-click actions
- Consistent keyboard defaults (OK = enter, e.g.)
Perhaps it isn’t possible with the chosen platform, but … dare to dream!