The deck I made from 2015 is slightly different than the "optimized core2k6k". From what I can see the only difference is that some of the English translations are slightly different, and some sentences in Japanese are different. There's also one more sentence for あげる showing a 5th meaning of it (there's like 10 or something) so there are 6000 cards instead of 5999. Also it lacks furigana readings, just the full sentence in hiragana. There may be other changes and corrections. I figured it likely that the most recent version is the most correct, so decided to use that.
Edit: From what I'm seeing now there are a few mistakes in the 2015 version which are corrected in some of the 10k decks that are floating around. For instance, 剥げる (hageru) using an extremely rare non jouyou kanji 剝げる (core 10k uses the correct one).
Edit: From what I'm seeing now there are a few mistakes in the 2015 version which are corrected in some of the 10k decks that are floating around. For instance, 剥げる (hageru) using an extremely rare non jouyou kanji 剝げる (core 10k uses the correct one).
Edited: 2015-10-21, 2:21 pm