Pros:
-They're sweet, sensitive old souls in my opinion
-They are very empathetic and intelligent birds
-If they trust you they bond very tightly and seem to be able to read your mind, becoming very sweet and sort of goofy
-Cuddly---Jacko is a snuggle bunny and requests scratching often---she also crawls under the covers and cuddles close to my body, then falls asleep
-That sort of intuitive, deep bond is something I haven't found with other birds
-Quieter than other similar sized birds
Cons:
-Emotionally sensitive and complex---they are not easy come easy go birds, they are needy
-Self-destructive if something isn't right, these guys are known pluckers
-Very cliquish, they know who 'us' versus 'them is and don't like pets/people who aren't one of the group, so they are not party birds or good for households with other pets
-Conniving---they know exactly what noise you hate, how to use it and how to get what they want and pull the wool over your eyes---that intelligence isn't just for talking

-Introverted---the only person who will see the goofy sweet bird you know--is YOU----strangers will be given the cold shoulder
-Cautious and prone to fears/phobias
I love greys, but they're not for everyone. If you want a grey in your life be prepared to be a lifelong guardian to a very precocious, self-destructive, emotionally sensitive, intellectually-gifted but special needs child.