I think it's easy to only see the faults in these tricorders because Diamond got them 95% correct, and it's easier to focus on the 5% instead of seeing just how overwhelmingly good they are.
Think about it from a different perspective: If a member here offered an unbuilt parts kit that was just as slightly INaccurate as the body parts on this toy is, and offered NO scanner, and NO electronics, and NO strap, and charged only $50 for it, there'd still be an interest list a mile long.
First of all, NO ONE has ever done a TOS tricorder toy even close to prop-quality. That Diamond has done two, and hopefully three different versions is pretty groundbreaking. I don't think it's hyperbole to say that this is probably THE greatest toy prop replica ever released.
Correct size and shape, sophisticated electronics package, and spinning moire pattern is already a BIG win for me, so I can forgive that the medical scanner "only" has sound effects. And I have to say that the scanner physically looks great. Down to the foil stickers and red lines they really nailed the look, and the grip also looks pretty darn accurate too. I don't care for the bottom of it, because that battery hatch and sound vent really looks toy-like, but I think I'll make up some kind of graphic to put on the bottom to cover that up anyway.
If I had the extra cash, I'd be stockpiling a couple cases of these, 'cause the demand is only going to increase once more people figure out they can have an accurate tricorder for $50. And it's likely that only this first release is going to have this level of quality, if the endless re-releases of the phasers and communicators is any indicator.