I love mine.
I haven't used it at Disney yet, but I have been using it for a few weeks, both for going back & forth to work, and for sightseeing and a conference in Chicago (museums, shopping, walking a TON, restaurants, visiting with friends, attending conference sessions and expo, etc).
The strap is wider than I expected, but once I played with adjusting both sides of the strap and found just the perfect place around my big chest (had to fix that - didn't realize what I'd said was a 'bad word', it was modified) and big butt, it fell just right. I haven't had to adjust them anymore.
I had a much longer review typed out but I hit my mouse and it wiped out everything I'd typed. In general - I love the pockets/the size (fit my file folder with travel information, magazing and book for the flight in the big pocket which was unexpected - I didn't expect it to hold those so well without bending corners).