We have had our GSC for 18 of her 19 years. She is a true Galerita, the nominate Greater from Australia. She is a true homebody and seems to enjoy a fairly rigid schedule but will be boarded without too much of a fuss by our vet. They are somewhat like crows in Australia.
I should think they would be a little easier than an Umbrella but, as you said, they can be as different as day and night. Regardless, I wanted to thank you for caring for them and welcome you aboard. There really is a wealth of education to be had here and I hope you can make good use of it.
Our bird is pictured on the Greaters in this taxonomy.Cockatoo Classifications