It's like an oversize sickle bar mower. Why not just have it continuously running back and forth? Somebody wasn't thinking at all about hose routing either. The hoses hanging right in front are just waiting to get mangled.
The stuff they show the BrushShark cutting are easily cut with a regular brush mower. I don't really see any benefit unless you want to take three times longer to get a job done.
For a little bit more, I got this: http://www.prowlertracks.com/attachment-swing-mower/
It's a bit more versatile, allowing you to reach over to ditch banks and cut overhanging limbs along roads and trails.