The 600se is more like a specific version of the Mamiya Universal, made by Mamiya for Polariod. The most significant difference is a different lens mount, and that the Mamiya has a wider selection of lenses (the 50mm, 65mm, 100mm and 250mm lenses are only available for Mamiya). I believe the back adaptor system also is different, but the 600se can use Mamiya roll film holders with the appropriate adaptor.
Originally Posted by StoneNYC
Great cameras in any case, although large and heavy.