If you are in a hurry use the mp4, otherwise use the original.
Thanks Ann for taking the time to answer. I'll do a little testing with both formats and see how they come out.
have a great day!
Unless the converted footage is lossless (which .mp4 isn't), you're always better off using original footage.
If you have the 2 original Projects you are golden...
Import one into the other and you have your edits and your source footage all in one place ready to combine as a new edit.