Nels, yes i have used Bambino Mio nappies. According to me they are the best of the best, also the most expensive. The problem with them is (the price...) that the waterproofs work with velcro, I used to see this as an advantage, but am so sick of velcro now, I never want to see another velcro nappy. The velcro gets full of fluff etc and is damn hard to keep neat if you wash as often as you do. If you put it in the tumble drier (by accident!) the velcro curls up and is basically useless. Plus you have to buy bigger proofs for every stage and bigger nappies for every 2nd stage.
The Econobum uses poppers and you use the same proof for all the stages as it can be adjusted to fit the baby at any age.
I think the Econobum is to big and bulky for a new born, I would still use the Bambino Mio nappies for new born, up to 3 / 4 months, then change over to Econobum.
But your son is big already, so I would go for the Econobum straight away, will work out MUCH cheaper than the Bambino Mio.
You might have to use a double nappy at night.
MissesMom: Earthbabies single soakers. They can hold 1 pee, the second pee will make the clothes wet. So I would use that during the day for actual potty training, they are like underpants, just padded so that a accident doesn't leak down the legs but they still feel wet. Mother nature also makes potty training pants, but they actually makes the clothes wet after the first pee, so not as good as the earthbabies.
At night I would use a double Econobum, its the only nappy that can keep my 2yo dry over night (not even disposables keeps him dry).