J.H.
We had a Kettler for our kids (and I honestly can't remember which one it was), but one problem I had with it was that when you push the tricycle the front pedals did not move. So my kids took a LONG time actually getting the concept of pedaling your feet to make the tricycle go. I actually ended up wishing I'd just bought a classic Radio Flyer trike, which would have been much cheaper too.
Of course I never checked to see if the design of the RF one had been changed in the 35 years or so since I'd had a tricycle - maybe they all have those coaster pedals now? But it's just something to think about.
Also the latch that held the back bucket broke at one point so it would just drag the ground behind the tricycle.