On one trip (2001, I think?) we bought Photopass and didn't think we really got the value out of it. At the time ride photos weren't included so we didn't really look at them, and I didn't think they'd be that special anyway.
Most recent trip, we did memory maker with extended family and the ride photos are by far a favorite! They turned out pretty darn clear, though there are times someone's face is turned the other way or blocked by another rider. It's really the kind of picture you can't duplicate in any other way and I like the borders you can add that put the name of the ride and date around it.
I'm pretty cheap and still don't know if I'd look at each picture and think "sure, I'll pay $15 for that" (multiplied if the whole Fam isn't in same shot) but we rode every ride that has photos, met some characters, posed at least once in each park for pictures in front of icons and really treasure all those photos. After the trip when I just have a fading sunburn and a new Mickey t-shirt, the MM felt like a very worthwhile spend to me!