Best to modify the default or create a clone of object styles when creating new project templates?

Hi.  If I am intending to create a new Project Template for each project, is it better just to modify the built in Default Object Styles to my liking or is it better to leave them intact and create clones in my preferred project style.  Is there any benefits of doing it either way?  Also I may want to import a set of object styles into a new project if it is quite similar. Much thanks.