What is wrong with the Hoverboard? This is the first I have ever heard a complaint about it. I did not even know it had shipped.
Hoverboard has yet to ship, but there's a long list of problems with it based on the final version shown at NYCC. The best bet is just to get you to read from here in this thread on therpf.com so you can see the issues for yourself.
Let's just say that the "100% movie accurate prop replica, down to the smallest detail" we were promised when preorders opened for it has become "a really cool toy" (Toyguru's own words) now that it's time for them to [refuse to] deliver on their promises.
On top of that, when some of us voiced anger over what was a bait and switch, Mattel tried to lock us into it, citing clauses in the preorder which was null and void due to their failure to deliver. The only thing that seems to have changed it was a member of therpf.com contacting Mattel Legal and compliance. Within days of that, Mattel suddenly did a backflip and allowed cancellations.
Even then people have had cancellations refused over email and have only had success when they've actually called Mattycollector and threatened legal action (which is what I had to do).
Let's just say after Mattycollector's borderline fraudulent behaviour; I'm more than a little hesitant to trust them again with something costing more than twice as much. People say that Castle Grayskull will be different, but then we all thought that with the Hoverboard too...