I've had Luna for a few weeks now and her personality is drastically different from my last green cheek, Bandit. She's super independent, hyperactive, very rarely cuddly, and not a big fan of scritches. Bandit was my little velcro baby and she preferred to be on my shoulder every minute of the day. She was very laid back and very sweet. Individuals vary, so you never know what you'll end up with ahead of time.
That said, green cheeks are fantastic birds. I'll have ten of them one day, I promise. They're generally very quiet and even when they do make noise, it's not very loud. They have a lot of big bird personality for such a tiny size. They're playful, fun, smart and easy to train. They do go through a beaky/nippy stage as babies and again when they hit puberty, but if you work with them using positive reinforcement, clicker training, etc, you'll get past it relatively easily.
I would say that green cheek conures are slightly higher maintenance than cockatiels, but still much more forgiving than some of the larger parrots.