Interesting take: Rewarding is in the eye of the owner. As mentioned, they are a LOT of work. Having only owned conure in the past, by comparison my eclectus is extremely high maintenance, and I find I'm still emotionally adapting to the amount of work required. for some people, The amount of work required doesn't feel that rewarding; all they see is work.
For others, the warm fuzzies you get in taking wonderful care of a fantastic creature are extremely rewarding.
Me? I'm in between. It's been 5 months and I'm still adjusting. Almost where I need to be emotionally, but a larger parrot has been more daunting than my conure ever was. My Parker has his forever home and his devoted slaves, but it's taken some push to get there.
ITS NOT FOR EVERYONE.