I basically agree with you. The entire enterprise felt like a thinly-veiled cash grab. While there certainly are a few sporadically funny bits, most of the humor falls flat. The actors too seem to be phoning in their performances as Bullock especially seems to get more desperate as the film progresses, perhaps realizing the tired project she got herself into. As her sidekick, Regina King is also lackluster; failing to deliver a consistent personality to her role as she instead sees fit to play back on the stereotype that is her character. Like you said, the Vegas show routine late in the film is tired and seems to last forever. Recommended only as a matinee for fans of Bullock and a rental at best for others.