My 6 year old just grew out of his Belter Trail. It was the same bike as in the review, but I put a little higher rise in the bars and used different pedals. Good components throughout, and the belt is nice if your putting the bike in a trunk or back of a car (no messy chain). After a year, there are some scratches on the brake lever clamps, but that's about it. It held up really well. It's easily a better run-bike transition than the spawns or any of the major production bikes that I've used with my kids or my nieces/nephews. The thing just doesn't weigh the little guys down.
The gearing was a little tough for him to start on any kind of incline. He would walk up to the next hill-top and start from there. I wish they would have dropped the front ...beltring? to a slightly smaller size.
I just washed it up to bring it into Red Shreds for consignment and it looks great. I thought I'd have to swap the cables to smooth-out the brakes after a year, but they're still perfectly smooth. They actually used nice, smooth stainless cables and decent housing.
The bike was pricey, but it's basically a tiny high-end XC bike. Yes, the tires would be better if they were bigger, maybe a 2.25 would have been perfect. After that, the brakes would not likely open up enough to release the tires. Not that I ever took them off. It did look pretty cool with an old Chromag stem and seatclamp on it.
Decent kids' bikes are hard to find, great ones are exceptionally rare. This one was great.