haha. is this strange timing? last year, in june 2011, i was in NYC and found at a used book-store both volumes of the Bartok edition for sale. i bought them because i had never seen it in print before, not even my conservatory library had it, and they had many obscure things.since then i was inspired to learn and record the entire WTC. you can find my recoridngs, which i posted here, by going to my Audition Room Index link in my signature. i learned them all in bartok's order, just because i wanted to be surprised by whatever one came next (i never looked ahead until i recorded the one i was working one).the bartok is supposedly arranged for the benefit of students, while he was teaching in Hungary, in order of difficulty. there is a lengthy intro and some other text, but it's in Hungarian and I can't read it, and haven't had it translated yet. i have a lot of thoughts on this edition.one, if it is arranged by difficulty, it is possibly arranged by compositional difficulty above piano technique. the first fugue, G major Book II, is quite tricky; the last one he rates as "most difficult" is B major Book II, which technically is really not hard to play. for me, the hardest ones technically are b-flat minor Book II, and a minor Book I. however undoubtedly the compositional aspects get more complex as you go forward. G major Book II, the first one in his set, is really simple from a fugal point of view.two, i think he never really completed the project. i say that because a lot of preludes & fugues are marked up with extensive expression marks, and have footnotes at the end, but as you get dfurther into it, there is less and less editorial markings. also the fact that B major book II is at the end makes me think he probably didn't even get around to ordering all of them.three, the most interesting and for me useful part of this edition was his insight into bach's meter, which should not be surprising considering Bartok's art. in several of the preludes and fugues that he edited, he editorially adds meter changes in the piece to show how bach's phrasing stretched over seemingly irregular periods of time, but always came out right in the end. this inspired me to go in-depth with the preludes and fugues he didn't mark, and find more subtle changes of meter that add so much to interpretation. i can give you some examples if you want.i need to get the text translated to find out his real goal and thoughts. i have to say, i don't find it an essential edition, unless yo ucollect editions of WTC. i think the Busoni on the whole is more insightful, but this one has something to add.i hope you go over to audition room and listen to some of my WTC recordings, it was a project a year in the making - i just finished last week.