With Aria, the centerpiece of MGM Mirage's (NYSE:MGM) massive CityCenter project, opening earlier this week, I decided that it was high time for me to head down to the gargantuan new installation and see what all the hubbub was about.

To be sure, behind the polished veneer of the place, there are still a few kinks that need ironing out. For instance, a fancy touchscreen menu outside one of the restaurants happily displayed the "always breakfast" selections, even when I tried to view the lunch and dinner menus. And while employees were friendly overall, few seemed to have a full grasp of what was going on and where everything was.

But the splendor of CityCenter far outweighed any small opening-week fumbles. Even for a Las Vegas resident who has been jaded by The Strip, Aria didn't fail to impress. If nothing else, the building is visually stunning, with a sleek, modern look that makes many of the aging casinos along Las Vegas Boulevard look like rundown houses.

And there were plenty of visitors checking out the newest Las Vegas attraction. Not only were there mobs milling about the casino floor, but plenty of people were seated at the slots and table games and in the poker room. Talking to a front desk clerk and hostesses at the restaurants, it sounded like there are plenty of rooms and dinner reservations to be had, though low-end rooms at $149 per night and new, unexplored eateries will likely attract both guests and diners in the coming weeks.

Of course, while my opening-week observations dispelled my suspicion that CityCenter would be less than the mind-blowing marvel that MGM management seemed to expect, the proof will be in the earnings pudding over the next few quarters. While curiosity about CityCenter may inspire some additional tourists to flock to Las Vegas, I imagine that the property may find itself locked in heated battle with other high-end Strip operators like Wynn Resorts (NASDAQ:WYNN) and Las Vegas Sands (NYSE:LVS) -- not to mention other MGM properties.

Meanwhile, while luxury goods like Coach (NYSE:COH) purses and Tiffany (NYSE:TIF) jewelry (which will be sold in CityCenter's shopping zone) may seem like tougher sells to tighter-fisted consumers, the same could be said for a vacation to Las Vegas' newest, hottest resort complex, where dinner for two can cost more than a low-end computer.

If MGM had it to do over, I have to imagine that it would at least have wanted to run with a scaled-down version. Nevertheless, CityCenter is huge, it's shiny, and it's definitely here. What remains to be seen is whether financial results justify the $8.5 billion price tag.

So maybe CityCenter wasn't MGM's best investment ever. But we've all made investing mistakes. In fact, Dan Caplinger recently invited Fools to share their worst investment mistakes of 2009.