I visited this buffet twice during my visit to Las Vegas in January 2017. I had received a discount for a weekday breakfast and a weekend brunch. I ate here in one of my previous Las Vegas trips so I was familiar with the type of food offered at this buffet.
The line-up for my weekday breakfast and my weekend brunch wasn't too long. I had to wait ~15 minutes to get to the front of the line where I presented my MLife card containing my discounted meal.
As buffets go, as mentioned, I would say that it is similar to Monte Carlo's buffet (maybe a bit larger in terms of area). It is self-serve for the soft drinks and juices. The drink dispensers was exactly the same as Monte Carlo's buffet so you had Diet Pepsi, Pepsi, Root Beer, etc. The machine was not as fancy as the one at the Mirage.
I'm not sure whether I would pick Excalibur's buffet if I wanted to have a relatively inexpensive buffet (when you compare it with Strip buffets). I would probably go to Monte Carlo just as a personal preference for that type of buffet. There was nothing bad about the buffet but there was also nothing that I was overly impressed with.