The Best of Times would have felt more like an attack on Portnoy. Playing one of the most cherished and loved DT epics so many years after it was last played (Hell, I follow Dream Theater since 1999 and I've seen the song live only ONCE, in 2000. That was 17 years ago. There are people who were born the day I heard A Change of Seasons live that now are having sex) and as encore of a show where they play the album the song was supposed to be on, it seems just a long overdue return to the setlist.
Also, since DT are supposed to play ACOS to spite Mike, is the whole Images and Words celebration just an excuse? "We have to play ACOS, that'll show Mike... but how? hey, how about this: let's play I&W in full, so everybody will see the song as tied to that era!"..... to put it mildly, it seems VERY unlikely to me.
About the show: how did the transition from This Dying Soul into Root go? did they just stop to play Root's intro over the PA like it happened on the cruise or they connected the two songs?