I had them as kids, then a coworker gave me a pair that he kids had lost interest in. The cage that came with them was huge, so I got 2 more. They seem quite happy - they sing and chatter all day long. They are messy, but if you get the cage guards, that helps contain the seeds. Also, if you put the feed cups low in the cage or on the floor (provided you can put them where they don’t get pooped in), the seeds don’t get flung around so much.
I give mine several dishes of a quality seed mix, plus millet sprays and frozen mixed veggies. And they love cherrios or other cereal, and sometimes grapes or a slice of apple. They also love plain steamed rice - I save some for them when I cook it for myself. I provide several feeding stations so that the more dominant birds can’t push the more timid ones off the food.
Once a week or so, I pull out any poopy perches and clean them with a 10% bleach solution, and clean the bottom of the cage. Keeping the bottom of the cage clean and clear of seed hulls helps keep the mess contained. I have an extra set of dishes that I run through the dishwasher as needed.
They are entertaining little birds - their noise and mess level are not too bad, as far as birds go. They are pretty easy to care for. Most live 5-10 years, but can live longer.
Be sure to buy a cage bigger than you think they need - and also make sure the bar spacing is 1/2’. The bigger bar spacing is for bigger birds. Also, you will want to provide perches of different materials and thicknesses. It’s healthier for their feet, and a concrete perch will help keep their nails trimmed.