Let me say first, I am not a breeder and have no interest in becoming one. I just love cats and have had cats my entire life. Echo has been with us 8 1/2 mths.
How safe are they around children, anyone have issues with any aggression?
Don't have children in the home anymore, but any animal is an individual and most can be taught to play nice and proper manners as long as you understand that they need outlets for instinctive behaviors such as scratching posts and appropriate entertainment. Aggression? Normally, only in self defense. Someone backs you into a corner or scares you, your going to react and defend yourself as will any animal. My experience has been they will retreat before reacting and if they do react, it's only out of fear and you didn't heed their warnings and body language.
Has anyone had issues with spraying from a cat that was fixed at a young age?
I adopted my F2 at 2 1/2 yrs old and was told he had inappropriate elimination and spraying. He was already altered prior to 7 mths when they got him. Not once has he ever displayed either behavior in our home. Give them a kitty box with high sides, which is common sense if it's a tall cat (I use a storage bin with a hole cut in the front with split fish tubing around all 4 edges so he doesn't get scratched. Storage box is close to 2 ft long because he is a large boy) with at least 4" of litter and I clean it daily.
Can they go outside?
Only in an enclosed area, including the top and I would suggest watching them very closely for some area you may have overlooked. Any cat will has potential to be very creative in going where they want. I have always been of the mind "Would you let your young child roam and risk getting lost, stolen or possible killed? No? So why would you let your pet?" Pets deserve the same treatment you would give a young child. Both are a lifetime commitment. It really is like having a 2 yr old around.
And, compared to other cats, what is the best and worst trait of these animals?
Best traits: Way too many to list! Having a SV is the most awesome experience. Just the sight of him warms my heart in a way that I can't even explain. My boy is entertaining and curious and has so much interest in everything around him. He loves our Bengal kitty so much and is very protective of her, tolerates her and her antics. When she was spayed and couldn't jump onto the bed, he scruffed her and put his paw behind her to help her up and cuddled and looked after her the entire night. It is amazing how gentle he is with her.
Worst trait: It really is like having a 2 yr old around. If they can knock it over, crawl into it, jump on it, play with it or drag it off, they will. It's actually very charming and not a bad trait at all. Pretty cute actually. Just have to remember that interaction is on his terms and what he's comfortable with at the time. People are individuals, so are animals.
You have to spend quality time with them. If you can't, don"t get a SV. If you can, you will never regret it.