I've got one of them and agree that they sound terrible. My preferred box is turpin/hen box style, so I'm very familiar with running a box like this Gibson replica.
It's terrible. But... could still call a turkey. I've heard worse from a real hen. A randy 2-year-old spring gobbler will come to almost anything if the mood hits him right.
The box may not sound 'good', but it's a nice piece to have in the collection to reflect on days past.