Our 5 years old daughter has set up board game boxes and was constantly playing on them 1 year ago when watching Youtube videos. Her motives haven't decreased for weeks so we started to think about buying an item on which she could start to learn. Yeah, I could tell it's great she need no board game boxes anymore, but it's really appropriate for satisfying this only goal.
The rims are really small, even for a little child, but the bigger problem is, the snare can't be turned toward the little drummer. So hitting the snare without touching the rim is quite a challenge. If You have a little fantasy You can alter the environment, e.g. I put the holding bracket of the snare on the left hand side where the hi-hat is (so it comes not from the front, rather from left, so the snare can be turned towards the drummer). The other problem with ergonomy is the weight. It's so lightweight, it always wandering in time and space, making an entire event unenjoyable. I holds more for the pedals, they're moving all around the neighbouhood. I had to make a plywood base under the whole unit and the chair routing the silhouette of the pedals and the holes for the knobs on the main rim.
The properties and sound are in a strong coherence, there are some predefined sounds but the volume levels are just simply ridiculous. The snare is barely audible when hi-hat is loud and harsh, and there's no EQ for tuning this very simple property. I think there's no need for (or no legit requirement of having) specific tuning features for an entry level instrument for a child, but the opportunity of altering the volume levels is a must have. And yes, for this price it should be an instrument, not a toy, it must not be an explanation.
As a summary, spare some further euros and buy something bigger for a child, he or she will grow into it, until then, You can add extra height under pedals, or boost the height of the seat itself, whatever. This e-drum can be useful, but only with major upgrades, not to mention the luck I have an FMR compression to even the volume levels a bit. Thus, it is bearable. But does a general user have a €300 extra unit, and does have the knowledge how to set it up for improving the sound of an e-drum which should be an inbuilt feature?