I am tempted to go back to ArcGIS 9.3 from ArcGIS 10. For what I do, 9.3 is more efficent. Now...I know I cannot open ArcGIS 10 documents (maps, scenes) and layers in 9.3 unless saved as 9.3 file, but what about features and rasters I created in 10? Can I add those into any 9.3 document? Any issue I should expect?