They are very small and expensive. You could almost buy a 4ft tank with hood for the amount they cost. They are also not good for some bottom feeders, cories shouldn't even go in them!
They're alright... I've seen some set up really nicely, but I would never buy one. As Cheese pointed out, you could get a huge tank for the same price as one biorb.
I've never seen one before, but if you are just keeping guppys or neons or something, and it is at least 2 gallons.......I think it's alright as long as there is oxygen going in because the surface of air to water ratio is smaller than should be!!
They aparently have really good aireation and a 5 stage filter or something. Mines really easy to look after, they say you only have to do water changes every 6 weeks or so, although I do mine every 3-4 just in case.
Yikes I've never seen them before but that sounds bad. I thought mini bows were overpriced (and they are) but that sounds horrible. How many gallons is it? What comes with it? I can't tell much by the picture.