In my very humble opinion, uber chests are basically a joke. To higher level players, they are practically pearl chests. To mid level players - gold chests. To low-level players, chests that give this interesting belt with double mortar boost on it.
More often than not, when people get an uber chest, their uber items are just replicas of what they already have. Their gem output is minute (a bit like pro chests but that’s another topic), and uber pearls! Who wants uber pearls?
Not only are they terrible, they are also common. They can be found literally everywhere: Ninja, war, daily rewards, blah blah blah. I remember the day when I still had the thrill of opening an uber chest - now, no more.
Legendary chests are better because they give GEMS! Many players would drop from the lowest uber chest tier to the higher legendary chest tier because of it. It’s pathetic really. And progressing alliance levels to give uber chests in alliance rewards for ninja is no longer a blessing, more like a curse.
Something needs to be done. increase the uber gems in chests maybe. This is just what I think though, so feel free to comment.