Haven't personally used them, have seen them in action.  For indoor arenas I think they'd be great.  For outdoors, it's been my experience that you may find that you need a little more dig than these could provide - unless you've got really good footing that's less prone to packing down.

I use a combination of a row cultivator and a section of drag harrow behind my JD 4310 to get things just right - I like the flexibility of my approach so that I end up not to deep, not too hard.

Patrick