Encore, Aria, and Cosmopolitan are three of the newest casinos in Las Vegas. All three are considered successful, but they opened right in the middle of a severe slowdown in Las Vegas which didn't make things easy.
History might be repeating itself in Macau, as that city faces a downturn right as major properties are set to open. Studio City just opened, while Wynn Palace will be opening next year followed by The Parisian after that.
A recent New York Times article did a good job of chronicling some of the issues in Macau. The government restriction on table games at Studio City prompted Steve Wynn to show frustration. Macau's junket operators have also been under fire lately. A possible smoking ban could be another hurdle for Macau casinos.
I tend to be pretty optimistic on the future prospects in Macau. Somewhat like Las Vegas I think these new upcoming resorts might have a rough start but should find their footing eventually.
Even with the recent downturn Macau is still a much larger gaming market than Las Vegas. I think some of the government regulations will ease with time and these issues will be seen as minor growing pains. We shall see.