Some other advantages of the iDevice M8 over the LX M8 when used with iPhones/iPods:
1) The iDevice version should (does? I think it is a standard configuration for some already) work with the iPod Classic, as well as with older iPods that run iOS but not the latest iOS 7 like the Touch 3rd and 4th generations. Legacy device support may be important to some.
2) The iDevice version is designed to work with iDevices.. If for some reason your LX M8 doesn't work with your iDevice and CCK or Lightning-to-USB, Apple probably won't help, and I think it is a bit much to ask Michael at Centrance to help as he has a dedicated solution for you already available. You take a chance that something about your setup does not work with no recourse should it not work.
I think the second point is a little different than the issue of Apple pulling CCK compatibility away from iPhones in a future update. We don't know exactly what is compatible, nor is there any simple way to test all the possibilities. I've already experienced some DACs playing nicely with the iPhone, iOS 7 and CCK and some not, and the dependence is with differing sample rates.