Kurt,
As stated, it'll probably work mostly out of the box, however, because of the variations in the use of codes (functions) on Marantz receivers over the last few years to keep up with DD etc, you'll probably need to teach some. When you do, and the software releases, you'll be able to confirm that they are "clean" and noise free because when you teach a recognized natuve (RC-5/6/MM) code into the Pronto, it actually just creates a pointer to the actual RC code and shows the code as it's actual RC-XX format on screen, ie RC-5 5 103. If on the other hand, it learns the code along with stray IR noise, it'll display as "learned" on screen.
As per my previous postings, I suggest doing the basics now because the fancy frills and pretty bits are far easier via the PC software.