Hi micr0,
Fusion resolution : 2000
Output file format : OBJ
Output file size : 337 MB
Number of vertices in scan file : 3,922,912
Number of triangles in scan file :7,839,611

- Fusion resolution : 2000
And by using geomagic and selecting decimate command here are results :
1- the scan file has Imported in to geomagic ( David laser scanner Fusion resolution : 2000 )
2-Decimate using percentage : 50%
Output file format : OBJ
Output file size : 200 MB
Number of vertices in scan file : 1,962,146
Number of triangles in scan file : 3,919,804
3-Decimate using percentage : 25%
Output file format : OBJ
Output file size : 97 MB
Number of vertices in scan file : 981,665
Number of triangles in scan file : 1,959,901
4-Decimate using percentage : 12%
Output file format : OBJ
Output file size : 48 MB
Number of vertices in scan file : 491,211
Number of triangles in scan file : 979,950
5-Decimate using percentage : 3 %
Output file format : OBJ
Output file size : 11.5 MB
Number of vertices in scan file : 123,413
Number of triangles in scan file :244,986

- Using decimate command in geomagic
NARMELLA