Just last weekend I was at the St. Petersburg boatshow in FL and they were showcasing this product. I bought a few being skeptical, and after learning about the product I have a few complaints and I would like to hear anyone else's opinion.
They advertise "environmentally friendly" "you can drink from one in a glass" I did some research and they are being mass produced in China and contain up to 35% LEAD
http://www.wisegeek.com/what-is-lead-crystal.htm <-- a little about lead crystal
This company is false advertising and they better be careful because of all the bad news stories of lead coming from China.
Complaint number 2 - the one ounce sinker is the size of a 3 ounce sinker (extremely large) And when underwater they look like large jellyfish. So hopefully you won't get a sea turtle on the line!

Complaint 3 - On the most recent fishing trip with the sinkers, we had both lead sinkers and crystal lead and honestly there was no difference to the number of fish caught. I believe there were more bites using the lead.
All in all, I believe them to be less environmentally damaging than lead sinkers. However, they need to advertise their product differently, I will not not take my chances from drinking from a glass of these. Save your money and the environment.