glass filter media

Hi all: anyone heard of recycled glass filter media? The installer who replaced my liner carries it as one of his accessory lines. The manufacturer site says it's superior to sand or Zeolite for various reasons. Just wondering... have never heard of this before. Manufacturer site: http://www.glasspackfilter.com/ .

This is not an ad or a recommendation... I just wondered if this stuff is useful or is another "poolstore" type gimmick. It's fairly expensive, but not out of the ballpark.

Would appreciate any comments from folks who know about this or can evaluate it.