Elixer's new strings are called nanowebs, D'Addario's are EXPs. I just tried a set of nanowebs on my new Martin (000-15S) and liked the sound a lot, but broke two strings in the first week (mediums too). I've now got a set of EXPs on, which sound good too. Hopefully they'll last longer. A number of folks on the Flatpick-L have reported breakage problems with Nanowebs also.
Sandy