A puppet file contains artwork plus rigging information, so if you have a puppet file it is better to use. If you have an artwork file only, you have to do all the rigging yourself.
Note puppet files when imported make a copy of the artwork file and use that copy. So if you use Edit Original from the menu, you will be editing a copy. If you want to share an artwork file across projects, you need to import the puppet and then change the path to the artwork file name back to the original shared file. However I personally prefer having a copy because it would be easy to break other older projects with edits if you share the artwork file.