mini or maxi micro scooter?

[lulubooboo]

Am thinking of getting one of these t bar scooters for each of my daughters. Do I get the maxi for the 5 year old and the Mini for the 4 year old or just get 2 maxis?? I am worried that the 4 year old will be too big for the mini and it's a lot of money for just a couple of months. I am getting these in place of bikes as they are easier to control.
Any input?

my daughter is 4 and a half and has the mini (she's had it since she was 3) she is quite tall for her age and still manages with the mini quite well, but will soon be out-growing it.
John Lewis sells these scooters, so if you have one near by you could get your youngest to hop on maxi one, my daughter tried one at the weekend and the lowest handlebar height was not far off that of the mini.
Hope this helps!