My son got these last season and used them all winter. Size 5 feet. I was worried about the Onestrap at first, but let me tell you ...They work awesome!
They hold the boot into the binding just as well as any other multistrap system AND they go on so fast and easy, my 8 year old would strap himself in WITH MITTS STILL ON in about 15 seconds and be halfway down before I got my bindings done up!
If you are a parent who wants to spend time riding with your kids and not listening to them whine while you do up their bindings for them then these are THE BOMB!
I paid 100$ and they were worth every penny.