I would have much perfered Poser 5 to have overwritten my Poser 4 Pro Pack in the beginning so that all my library content was integrated into the program. This would have saved a lot of disc space and elliminated duplicate models. That having been said, however, since a lot of the python scripts I bought won't work in P5, (the walk designer is broken and there may be compatibility issues with Vue 4) I'm glad that it didn't work like that. I'm still using P4 for a lot and have been mostly been only using P5 for the Firefly Rendering Engine. Any P5 updates that come out offering new features, etc. I would perfer to overwrite existing files.