Tamron SP 70-200mm f/2.8 Di VC USD

Has anyone used the new new Tamron SP 70-200mm f/2.8 Di VC USD?

I have not used it, but find it odd that there are so few reviews of this lens.  Just two user reviews on amazon and by this point I would think we would see more.

I am considering the Canon 70-200 2.8 IS for portraits, but the idea of saving money might prompt me to go with the Tamron, depending on what people think of it.

Thanks