This mod features:

- Several trees around Whiterun 
- New fencing around Bannered Mare
- More immersive market area
- Several Benches and Rocks to reduce the dullness of the landscape
- Occlusion planes in the majority of static objects, improving performance
- A lot of hanging moss :)

Regarding performance:

Occlusion planes are an engine-integrated method for disabling the rendering of invisible polygons and textures.
It is the same method rgabriel used in his Skyrim Project Optimization.
These can be found in most large static objects throughout Skyrim to disable rendering behind said object.
I added these into smaller objects like Posts and smaller houses, resulting in a general performance boost.

This mod should atleast give you +-/0 Fps, because of the added details.

Tested on following machines:

1st:   mine                      average:  FPS +12
2nd:  buddy                     average:  FPS +7
3rd:  asenasen                 average:  FPS +5

These results may vary and I'd love to have your feedback.