So, the other set I saw wasn't a mistake - they actually didn't play Inferno...
...so, to recap.
Symphony X promises a "longer set" on this tour. So they add "The Odyssey" in hopes that it will deter people from realizing that they have dropped a total of FOUR songs from the longest sets of the European tour. (Inferno, Evolution, Sea of Lies, Prometheus)
So... this set is maybe 5 minutes longer. Nice.