I have a pair of olive pythons. Bought them recently as young adults. Mine are originally wild caught from NT and they are great to handle. They have their moments like anybody, but generally I love them. They are quite placid and don't seem to mind being handled. They are very different to a carpet snake. Carpets are graceful explorers where my olives are spirited and like to get from A to B as quick as possible with no stops in between. I've taken them out on the grass and they will climb up my legs and happily perch on my shoulders. Feed time is a different story. Mine are quite aggressive when taking their food. God help anyone who dares them while in feed response and watch they don't get you. They aren't easy to pull off if they happen to grab you.
What you want to consider though, Miley is their size. I know you say you're aware they grow big but you have to be able to afford to be ahead of them. Can you afford the enclosure size it needs - it won't need the big one first up so you'll have a couple of years to work on preparing their final enclosures. Olives require large feeds. Are you prepared to feed them guinea pigs or rabbits if you can't find suitable sized rats
And you have to know they are a large snake and you should not attempt to handle them on your own. Can you imagine 12foot of olive latching onto you, and when they do they will wrap themselves around your arm or where ever, and they are hefty beasts so be sure someone else is always around when you handle your snakes in case something goes wrong and they can help you with them.
Other than that, I can't fault mine, I love them, won't trade them for anything. Respect them and enjoy!
Now I should start practicing what I preach