FS, I've been testing this and the additional 1-0-1 Metagross d doesn't seem to be doing anything. In all of my matches, it's overshadowed by Meta DX; hence I might take the 1-0-1 out and stick with 3-2-3 Meta DX. That'd free up 2 card slots as well, and this deck is pretty tight.
Tego, I'm amazed you're finding this deck inconsistant. You have 10 good starts; 4 Casty, 4 Beldum, 2 Lati@s. With 8 Mentor you have around a 60% chance of starting with 1, although I agree it's hard without one if you don't get a casty start. Still very consistant.