I had the pleasure today of looking over the "Wondrous Treasures" product by Raging Swan. I was pleased with it overall. The work contains the sort of details one might expect to find in the Core Rules or a free web supplement but isn't due to understandable space limitations, repetition of information (such as stat blocks) and perhaps the lower frequency of seeing the standard magic items it covers (bags of tricks, figurines of wondrous power, horn of Valhalla, robe of bones, robe of useful items, rod of wonder) at play.
The download contains two documents, one optimized for print and one for the screen. They both looked great on screen anyway, on my PC and Nook. The black cover is something you'd want to skip printing. Somewhat of a minimalist myself, I actually like the simple black cover over flashy artwork as well as the simple black and white interior art and the clean, clear and concise formatting and layout. There were also no major errors or omissions.
So, if you handle characters who owns any of these magic items, this product may just be worth the price of admission by putting all the details right at your finger tips. Some might find the price a bit high as a "must have" supplement, since it covers such a small niche. Still, a lot effort went into organizing it and I myself would have no trouble paying for this.
[4 of 5 Stars!]