IMO, Sultans are a weak breed. My pullet got sick 3 times when she was very young. Gave her some VetRX and she was okay after all times, but still. My first roo got sick, and in his final hours of life, I left a cup in his isolated crate where he resided during his sickness, and he got his head stuck and didn't have the stength to get it back out.
I'd take it back if I could, a thousand times I would. What a good boy he was.
Before he got sick, when he was a young cockerel, he earned his name-sake. He was picked on by other birds-and they went after just one foot. So he became Fuzzy Fur Foot-for only having feathers on just one of his feet. But what a sweet boy! Definately my favorite rooster I've ever owned. The next winter a hen seemed to have a random obsession with his crest feathers and pecked most of them off. Needless to say, that taste ended right then and there and Fuzzy grew his feathers back in a few weeks. He took quite a few beating on several occassions. How ironic that his death occured when he was far too weak to save himself, when like many times before he found the hidden will to continue on.
Many don't suggest cresteds to begginers because they require different care-sometimes more care. They can have a hard time seeing in some cases which deter people from getting them. But really, I just give them haircuts and they're on their merry way. Very enjoyable birds. Mine have been friendly, human-trusting, and very rewarding. We're up north and they do fine here. I've never had any reason to doubt Sultans but Polish-although friendly-can be a little tempermental sometimes.