Easy! I'm not 100% film, and I use 35mm too. Dark churches get digital. Outdoor ceremonies get a mix of film and digital. The vast majority of my film shooting happens during the portraits with the couple, getting ready, and various other parts of the day where I have time. When I shooting portraits I have my 2nd either loading the Pentax or my Rollei, depending on what I hand him or her. I've been shocked at how much I like the output of my F6 though!
However were I to need to load much faster, having a set of pre-loaded inserts works fine with cameras like the Contax 645AF or Hasselblad H, Mamiya, etc... I'd just rather have a 6x6 and 645 in one! That I don't have to rotate!