Best rides for kids

Here is one of my grandkids riding one of the Honda's today. Mind you I have 4 grandkids. This is our 110 that I put a throttle limiter on and stuck it in low gear. All the kids did fine on it today except for one kid he high centerd a rock in the garden.
Anyway the reason for starting this post is to get some other ideas from you parents or grandparents as to what your kids ride. As far as I am concerned a trike is not the easiest to ride for a part-time rider. i would think that something with a centrifugal clutch might be a better option, let off the gas it stops. I have a 74 70 that needs some work to run top notch but even at that I'm not sure that is the ideal machine, plus the fact that two of them have outgrown the 70.
Just wanting to hear if Anyone has any experience good or bad with other machines for kids, go-cart 4-wheeler, mini bikes? I suppose with grandkids it's a new training lesson everytime they ride beings we are not together enough to give proper and effective riding lessons. Ideas and thoughts always welcomed. A few things I learned today.
Brakes both foot and hand are hard to operate for little kids .
Don't put your feet down goes against all of your protective mechanisms when things get a little out of sorts when you are a kid .
Kids have no fear at least 3 of the 4 that rode today.
90 nickolson Bored and Stroked "The Good"
Big Bore 110 Pauter frame "The Bad"
90 Bored and Stroked “vey’s frame” "The Ugly"
110 JSC frame Bored and Stroked
flat track build. “Shop trike”
1974 original 90 X 2
1974 Original 70.