As a kid in Vegas there were 2 things I'd look forward to...arcades and BUFFETS.
Through the decades I made my gradual move up from the MGM buffet to the Paris buffet onto the Bellagio and the Wynn. The Wicked Spoon took me into the next tier.
Prices will always be prices and at 35$ a person for brunch into dinner, you find yourself wearing off that charge with just the bone marrow. I've been to top rated places here in Southern California that run their bone marrow into the high teens and provided it with less richness than they do at the Wicked Spoon.
Now for the rest of their offerings you could argue them to be from average to pretty good and I won't disagree there. You're bound to try what you're going to try so I won't hype up any individual food but rather let you know what you can expect to come across on the negative side of the field.
The Fix
Their rendition of the Mexican chicharon picadita was disrespectful to all the street vendors in Mexico.
I loved the ice cream but the waffle cups had no flavor to them.
Their plate pick up and drink dispensing game was off at our table.
The omelette man was not too friendly, service overall was lacking a la Cosmopolitan style (refer to my cosmopolitan hotel review).
Their meats are alright, don't expect prime churrasqueria quality.
Number Don't Lie
Buffets are some of the most reviewed businesses on Yelp for the area of Las Vegas and I have found the star ratings to be quite accurate. The Cosmopolitan's buffet at the Wicked Spoon is a a 3.5 with their bone marrow convincing me to round it up to a 4. They provide a vast array of foods and the desserts are proportioned small enough to play dessert roulette without any leftovers. Come at least once if you're wanting to get more quality than 90% of the buffets made available to you here in Vegas. For myself, I'm rubbing my hands for the next couple months when I'll be trying out the Bacchanal Buffet.