I use it and it's great. I do not regenerate it, just replace it with a new bag every 4 to 5 months. Dr. Foster hast it for $8.09.
http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=4190
Got more today from Ken for $6.95/bag. I use one for each tank, 55g and 30g.