You can get all ride photos except 7 dwarfs without a magic band, but you do have to stop at the photo preview screens to link your photo to a photopass card. 7 dwarfs has no photo screens, so you can't get it. You also do not get the 7 dwarfs and Tower of Terror videos.
I like memory maker and tell people this list of items that helps make it worthwhile - the more that apply to you, the more likely you'll get a lot out of MM:
- a big family or travel group
- longer trips
- you'll be doing Jedi Training Academy, Enchanted Tales with Belle or Pirates League
- you'll ride the photo-enabled rides
- you'll stop to get photos taken at spots throughout the parks and remember to ask for magic shots
- you plan to meet characters
- you like to scrapbook or display photos at home or work
- you'll do character meals that have a photo before the meal (like Chef Mickey, Cinderella,s Royal Table, or Akershus)
