My eldest had a Rothan from just before his 2nd birthday - was a bit big then, but he wanted to push it around the house and in doing so got used to the weight and what it would do when he moved. Two months later, he was outside and doing fine and he's pretty small for his age. Didn't take long before he was zipping round the bmx dirt track near our house.
I considered putting a brake on the back of the Rothan, but didn't want to introduce too much too soon. He only ever had one proper out-of-control crash on the Rothan, but wore out the soles of his trainers in fine style!
He moved onto a Cnoc 14 a couple of months after his 3rd birthday and got the hang of it after a couple of trips up and down our street, the Rothan meant that balance was never an issue for him. Would recommend without hesitation.