They are amazingly beautiful although I guess super hard to tame and keep that way. So if you want a pet, they may not be a good choice. If you just like looking at and listening to them though, they sure are gorgeous.
They are beautiful birds. There are also crimson rosellas, western rosellas, northern rosellas, green rosellas and pale-headed rosellas. I don't know which of the varieties are found in captivity, but they're all worth looking up.