It looks cool, and you could conceivably do water changes but it would be WAY too hard to siphon.
Eventually matter would build up at the bottom of the tank and you'd end up with lots of waste.
I also don't like they way they advertised it as only has to be cleaned once a month, but I guess that has nothing to do with the actual tank since it's up to the owner to maintain it.
There were no filtration specs or anything either, so for all I know the filtration isn't adequate for much of anything.