The Luxury Flagship for GM kind'a misses the mark on quality. During the short ownership time (3.5 months) several significant mechanical issues were noted, not promptly fixed, with causes only the factory could correct (I can't blame the dealer). One issue took so long to repair even the "new - and free" loaner I had while waiting for mine to be repaired had the problem...
Great power, good size..ON-Star well worth it, nice technology
More creature comforts like Stereos and CD changers, Satellite NAV. on regular model not just one model.