With the recent interest in ceramics/fracking, Don sent me the link to CarboCeramics corporate presentation for June, 2013. Of course, this is a dynamic link and the June presentation will probably be there until the company posts a new presentation.
It certainly appears the jury is still out with regard to sand, ceramics, resin-coated proppants. It will be interesting to watch.
Also, note the references to "slick water," something that was mentioned/discussed on the blog a long, long time ago. The blog's search engine should be able to find posts mentioning "slick water."