I got MM as part of a bundle with my WDW tickets. I used it to set up an MM share group and photos are now appearing from members of my group in my MDE. (I don't go for another 13 days.)
I think the photos are surprisingly poor. Presumably there are people paying full price ($169 in advance, $199 otherwise) for this service and I can't see how they can be happy with it.
Sure, there's the convenience of having someone take your photograph while you're meeting a princess, so that your whole family can be in it, but I expected professional quality pictures. You know -- the group centred in the shot, people having their eyes open and smiling, that sort of thing.
Have you been happy with your Memory Maker purchases?