I saw this concert in '96 (w/ lead singer Dennis De Young), and recently in '04 (w/out).
They still play decently, but the '04 concert is also a cumbersome exercise in which the current band members try to downplay the absence of DeYoung (who was left off the band against his will) while cashing in on his memorable achievements.
The '04 Styx is more like a natural opening act.