It can be a little confusing, as all 3 versions of new FrancisFrancis X1 machines look pretty much the same. The good news is that it's pretty easy to explain.
The X1 GROUND machine is, as the name suggests, designed for only using GROUND COFFEE - there are aren't any adapters or modifications to allow it to use either ESE pods or iperEspresso capsules.
The X1 TRIO machine is designed for only using ESE PODS (the little paper covered "pucks" of coffee) - again, this is a fixed system so no options to convert to ground coffee or iperespresso. The ESE pods are available in standard roast, dark roast or decaf.
The X1 iperEspresso machine is designed for only using Illy iperEspresso capsules (the little plastic "buckets") - this is also a fixed system with no adapters or modifications. The iperEspresso capsules come in a wide variety of roasts.