After procrastinating for more than one and a half years, I recently took advantage of this offer. I'm very glad I did!
My test prints on ADOX LUPEX (processed in ADOX MCC developer) are very impressive. Their image tone is neutral without need for selenium -- exactly what I like -- and the surface is perfect. Just enough gloss to support solid blacks and not so shiny that reflections are a problem. I don't see any evidence of optical brighteners either.
If anyone is looking for an exquisite paper to contact print on, I strongly suggest making a small investment in this LUPEX sample package. It arrived here in California a mere five days after my order was placed, and would be well worth an even longer wait.