The Short Version: There are parts on this that could be easily broken and the the two buttons that make various features work are inauspicious, but it looks and sounds great. I would suggest it might be better for cosplayers then as a plaything for a young child.
The Long Version:
Let's get something clear here: I'm a grown up lady who takes good care of her possessions. Now granted, I am also a grown up lady who buys Doctor Who toys and admits, in a public forum, to occasionally carrying them around with her and playing with them... but that's not my point. My point is, even in my silliest of moods I'm reasonably careful with my possessions and I'm a little scared to take this thing off the shelf.
I wouldn't say that the item seems flimsy or poorly constructed, but there are lots of little ridged bibs and bobs on it that make me concerned I'm going to break it. In particular, I'm worried I'm going to snap the clear rod that extends along the bottom from the front to the ring, and the ring itself, when I hold the sonic screwdriver to use it. The little access panel, with the red handle, that you need to remove to access the neural relay and the button that changes the wavelength from blue to red and back, doesn't come out easily. It would be easy to lose the little panel or to snap the tab that holds it in place.
The button placement is a little inauspicious. As I mentioned, you have to open the little access panel to change from blue to red and back, that same button also turns on the "neural relay" lights. I would have liked it better if I didn't have to fiddle with opening an easily lost piece to switch from blue to red. Also, the button to activate the primary function is a bit fiddly. When one holds out a sonic device dramatically, it doesn't do if nothing happens because the button is too small and in a recessed area.
Now that I've groused at length like a good little nerd, I have to say that the whole thing looks and sounds great. Unlike any of the other sonic screwdriver toys this one actually has some "distress" included in the design and paint job. It has a much more "real" look then you usually get. When I turned on the neural relay lights and showed them to some friends who were also "Wholigans", it evoked a strong emotional reaction from them. I must admit, it's a little sad even for me to see the flickering green lights. So, well done there.
As I mentioned above, it looks and sounds great but the extra bits that can be easily broken means that this item is for older kids and cosplayers.