Two possible performance increasing options:
1) Materials and Textures are on by default unlike AutoCAD 2006 which can greatly impact performance but also produce a higher quality view in 2007 features. You can turn these off at the Dashboard or go to the Performance Tuner 3DCONFIG. This method disables all Materials and Textures all the time.
2) (recommended Solution) To get the performance boost while still having Materials and Textures use the Dashboard option Performance Tuner or 3DCONFIG then move the degradation order for Materials and Textures to the top.
Cheers,
Shaan from Perth Australia this week