“In terms of sheer special-effects firepower, Vegas blows Broadway away. As for traditional musical theater, not so much. The much-ballyhooed Broadway-West trend has fizzled out after “Avenue Q” and “Hairspray” flopped here. Jukebox smash-musicals (“Mamma Mia!” and the soon-to-arrive “Jersey Boys”) may be exceptions to the rule, but most of the tuners that pop at the box office in Vegas qualify as Broadway-lite, watered-down 90-minute versions of the originals, easy on narrative and heavy on glam.”