The trouble with "Eastern rite Catholic" is there are several "Eastern rites" in the true sense of the word. To use it as a synonym for Catholics who follow the Byzantine rite, let alone for the Ruthenian Metropolitan Church, isn't correct and isn't fair to the Armenians, Maronites, Copts, Chaldeans, Malabarese and Ge'ez Catholics--all of whom are "Eastern rite". It isn't even fair to the Ukrainians, Melkites, Romanians, Russians and other members of Byzantine rite Churches.
Stuart,
The problem is that most people like to take things one step at a time, and since most RCs are only vaguely aware that there is such thing as an "Eastern Rite Catholic," to try and go into all that with everyone who asks only leads to confusion, in my experience.
If they seem interested, of course, I'll give more of an explanation ...
Peace,
Deacon Richard