Quick Comparison Minor differences of 0.51 mm can occur due to manufacturing tolerances, but these are not unique to Japanese cards and may be seen across different print runs
I'm not against using it to self mill to get a win with Jace, which sounds like it'd be a VERY good win con combined with Archmage Emeritus, Thousand-Year Storm and Veyran, Voice of Duality, or to fill the graveyard for me to cheat something out with Narset, but I wouldn't really consider that ideal in that circumstance because the ideal situation (in my mind, at least) is I'm using Narset to cast something twice
It helps you load the graveyard too
Its the cheapest creature with initiative, and it helps you keep it
Additional ways to clue you in to some special, often valuable cards: Secret rares have a collector number higher than the total # of cards (supposedly) printed in that set, for instance "65/64" or "110/105." Secret rares can range anywhere from a couple of dollars to hundreds of dollars