I remember the first time I watched UP when it first came out I cried during the 20 minutes, but was unimpressed by the rest.
I revisited this film now soooo many years later in full, and to my surprise, not much has changed. I came dangerously close to tears during the infamous first 20 minutes, and then it was just meh until the end. Of course, there are parts that are funny and heartwarming, but all of its greatness is kind of shadowed by the brilliance of the Carl-Ellie scene.
Not my favorite Pixar by a long shot, although nothing else has been this reliably tear-jerking.
Couple years ago I went to a Pixar film concert, where they played the same segment and then followed by intermission. When the light turn on, everyone around was in tears or was trying to conceal the weepy eyes. What a stupid song lineup.