In vegas, there are things that you can count on.
1) you will lose money
2) you will see people handing out cards for escorts at night
3) you WILL see a popped collar
4) you can go to a casino and eat your fill and then some for not too much.
The Wynn buffet is a buffet that has lots of variety, quality, and is very clean. For dinner, they always have roast beef and crab legs. I'd say the only thing that is you really need to look for is the dessert and fruits. They always have some great seasonal fruits.
Last time I went here w/ my lady friend, we went for lunch and I can say, the quality seems to have gone down. Maybe I just remember it better than it actually was but it seemed like the quality went down.
My major complaint is that the servers here are not very attentive. It sucks even more that they kind of pressure you to leave the tip at the front when you pay for entry. I can't remember how many times I've been here and waited for 5-10 minutes to get a refill of a drink.
In the end, it's still my second favorite buffet in Las Vegas. You can get an unlimited course meal of good quality for a flat price. 5-stars but -1 for inconsistency of quality and poor 'ish service.