I was about to ask the same question . Some 17m? If it is cheaper than 15mm super wide Heliar - it would be nice to have it, as I use super wide lenses so seldom - the cheaper the better - that I can justify the purchase.
You betcha!
It really is quite liberating using this lens because you can't focus, you can't adjust the aperture. All you do is concentrate on the composition.
Tip - it really like contrasty/brightly lit scenes.