I didn't see the UTEOTW encore (stupid Cleveland selling out so fast!) but I did see the Zoo Station/Fly encore, and Zoo Station really didn't do much for me. I don't even really like the song all that much on the album, come to think of it. The Fly always is great. I think the Fly/UTEOTW encore that Boston had would have been the best option.
The best encore I saw was in Detroit on 10/25. The first time, Who's gonna ride your wild horses, WOWY, Crumbs, and Bad. That encore kicked ass!