Perhaps I should also add that this poor instrument is the one I take out my frustrations upon. It's been dropped and abused and has also survived being set on fire.
If you want to know what it sounds like, then check out this video that I put together this weekend:
I like the idea of minimalist instruments such as this. In a way it's a reaction against these guitars and basses with an ever-increasing numbers of strings just for the sake of it, rather than because a greater number of strings is useful musically or makes for a more playable instrument. It seems there is rivalry amongst some bassists as to who can have the instrument with the most strings. (And I'm talking about individual strings, not strings arranged in courses such as on a twelve-string guitar or the Hamer 12-string bass we looked at yesterday.)
You don't need a 7-string guitar - just listen to what a three-string can do. Sometimes less is more.