I don't know anything about them personally, but from viewing the pics online it seems like a well constructed unit. The immediate drawback I see is the need for electricity for the rotis, so you're limited as to location. This looks like an awesome unit.
I'm sure it's been done before, but you'd think with all of the imagination, creativity, and smarts on this forum, we'd be able to design and build a perfect grill.
PETA - People Eat Tasty Animals