jonny, both have potential if successful, only clinical trials will determine who has what and if it works. To date ACT has only treated one dryAMD patient. ACT stated in their Lancet report PR (below) that "Engraftment and increasing pigmentation were not detected in the dry AMD patient." ACT is in the very early stages and StemCells Inc hasn't begun yet. Clinical trials are long, this will be no different... http://www.advancedcell.com/news-and-media/press-releases/act-publishes-first-report-of-embryonic-stem-cell-esc-derived-cells-transplanted-into-patients/index.asp