Xref

 From:  andras
2698.1 
Hello Michael !

Just I would like to inform you that I currently work on an architectural competition project and my file size is around 150MB. This include only land sketch models and my building is not included. Actually I use the styles and it works well. However maybe in the futere an Xref feature would be more proper because of file size. The memory usage is around 500-600MB.