Bought this mask earlier this week, arrived today. I love its skull-like design, even if it doesn't QUITE fit the whole "mask of dreams" power visually. But, it was a commission so I don't begrudge that.
Anyway, onto the review portion:
I think the cross-axle might be a little bit long. Judging by its shape, it seems to work best with a Metru Head and not a Mata one, so anyone intending to use it should keep this in mind.
Also, the print I got had problems with the cross-axle not being well-defined and it had to be whittled down so that it would fit into the axle-connector on the Metru Head.
Judging by the 3D preview on here, I think this problem may have been a combination of a design fault and Shapeways' printing standards. However, as the mask did eventually fit nicely onto my Toa of Plasma MOC, I'm not really going to complain.
In any case, overall I really do like this mask, and am glad I purchased it.
Attached is a potato-quality photo of the MOC wearing it.