I would be surprised to discover that someone here has much negative to say about the "Big Green Egg". Although I do not have one, it was one of the smokers I considered before purchasing my WSM. My neighbor across the street has a Yamado and the ceramic smokers do a fine job.
The only negatives I can see, if you can call them negatives, are:
1. Capacity: Stock, it has a single 18.5" rack so has less capacity than the WSM, An additional rack can be added, but the same can be said for the Weber.
2. Ceramic parts can crack and break if it falls. The WSM may get a little chipped finish, or maybe a dent. I haul mine around and am not always as careful as I should be.
3. Plan on twice the cost.
On the positive side is, if you believe their website claim, that the charcoal lasts longer because of the superior insulating qualities of ceramic over metal. There are also those that prefer the aesthetics of a ceramic thing over a metal thing.
BTW, I note that there is a Chet over on the "Big Green Egg" forum. It's not me.