Got a box of macarons for $16. There were eight pieces so essentially it was $2 per macaron and they were pre-packaged and it looked like they were pre-made too. http://www.yelp.com/biz_photos/H8qpFitIesth86zqR4cwYg?select=hlElK7wkfQUNZuRO8VkA6Q
Raspberry - you can feel the pre-madeness, definitely not fresh.
Pistachio - the same feeling here, crusty, just off.
Chocolate - nope. Same comment as above.
Coffee - valiant effort, nice coffee flavor, but again, this just didn't hit the mark.
The macarons itself was a 2 star product, but the store overall was a 5 star. Lots of other stuff you can choose besides these old and stale macarons. They have plenty of fresh pastries. They have the world's largest chocolate fountain which was pretty neat. And they have a train locomotive completely made of marshmallows.
They also serve croissants and other extravagant stuff here. It's ok to splurge a bit since you'll be walking around anyway. It may be hard to find, but first find the conservatory and it's behind that. It's probably the less frequented areas since it is off the casino floor.
But if you do decide to go here, don't get the the macarons. It's pre-made, overpriced, and it's not even made by them. Label says, made at Aria. Stick with the fancy stuff they have out on display. Looks fresh, looks meticulously made, and if you're paying $6-8 per pastry, I'm sure you getting your monies worth.