What is the best method for improving speed for large assemblies, over 500 parts? Is it best to open the assembly in large asembly mode or lightweight. What does large assembly mode do for you compared to standard modeling mode?
For large assembly mode to help you, you have to set up at what time it recognizes the model as a large assmebly. Another thing you can do is load the model lightweight. It will load the outer shell but not the total model. When you need to modify a part you click on it and that will bring the full geometry into memory.
Also you can set up simplified configurations with all fasteners suppressed. You can have area specific configs that will have just certain components of the model load...
There are many to help the speed of large assemblies...these are just some of the ones I remember.
For opening large assemblies I would first load the assembly in Lightweight, then resolve the parts as needed.
To improve assembly drawing performance make your views in Draft quality and load the drawings Lightweight as well (Only works in SW04). You can set an option in the print menu to convert draft quality to high quality upon printing the file out.