Blessedly wood, and held together with standard, tightenable Allen bolts, rather than %$#$ Philips-head (or worse!) screws biting into and destroying the wood. Ahem.
Adjustable seat height (also with Allen bolts).
Rolls nicely! It's not exactly a "balance bike," since a) it's a trike and b) it's a trike. But similar in concept -- Flintstone style propulsion reduces the odds of kid achieving escape velocity, while still being plenty fast to generate serious grins. Also, brake is intuitive: Feet down = stop.