While I have no particular insights into the Japanese level of Heisig, I think I can understand where ruleof7 is coming from. I’ve studied Japanese for several years now using a variety of tools and methods. I’ve used classes, textbooks, grammar dictionaries, Anki, native materials etc. I’ve switched my phone, computer, game consoles, etc. to Japanese. I read Japanese novels, manga, and news articles, listen to Japanese music, watch Japanese TV and movies, play Japanese video games, write in Japanese, and speak with Japanese speakers. I’ve passed N2 and N1 of the JLPT and 4, 3, and Jun-2-kyu of the Kanji Kentei.

Taking all that into consideration, I would say my experience has been that my progress has been very incremental and that after all these years, there are still blind spots and gaps in my knowledge. I’m still studying and learning, and while I can see progress being made, I still haven’t reached what I would consider a satisfying level of mastery over the language yet. During the 7 1/2 years of my study I can’t point to a single period of unusually rapid acquisition. Also in my journey, while all of the methods and approaches I have listed above have been helpful, and some I would consider crucial to my progress, I wouldn’t call any single one of them a magic bullet to rapid fluency.

From what I’ve read of ruleof7’s experience on here and on his blog, his experience seems not dissimilar to mine. And I can say that when I see a claim of rapid fluency or of a one-stop “magic bullet” approach to learning, I too am reflexively skeptical. I freely admit that the skepticism may not be called for in all cases and may not always be fair, but I can’t deny it’s there.

As a disclaimer, I should note that I’m not saying that it’s impossible to learn faster than me. I’m certain that it can be done and has been done faster than me. But, that being said, I cannot deny that because of my experience my skepticism is triggered by any fluent in <3 years or one-stop foolproof method claim.

To conclude, and to agree with a previous poster, it is a good thing that Heisig didn't write anything about the Japanese language (apart from RTK) which proves that he does not share the same stage as people like Khatzumoto (AJAAT) and Benny Lewis (3 month fluency).

I was able to go and chat with Mr. Heisig at Nanzan in 2012. Nice guy. Smokes a pipe. Has a wonderful office. My background is philosophy/religion also, which is what we mostly talked about, but I did mention RTK to him and he seemed quite pleased that it was maintaining its popularity. I think the royalties are not too inconsiderable. But yes, he has very little to do with language learning in a professional capacity. He has somebody else take care of the managing the publishing and royalties of RTK, RTH stuff for him I assume.

As for his material published in Japanese, -as far as I know- the previous generation of scholars who came over in the seventies, including Maraldo, Kasulis etc., write pretty much exclusively in English, and then have people translate their work into Japanese for them. That may be a bit different for the next generation of foreign scholars in the Japanese philosophy/religion area. For example, Bret Davis would mostly likely write in Japanese directly. A German research student who attended my dept. also wrote and presented in Japanese (and he was an Anki user). And tooting my own horn, but I wrote my masters thesis in Japanese (although I paid a friend to read it over and fix grammatical mistakes).

The previous generation of scholars from the states mostly can't really speak that well is my impression. But then, they grew up in a very different world when it came to the availability of learning materials, and what was expected of them. It also just reflects the reality on the ground. The work coming out of places like Nanzan is going to be written in English. The community there are also going to be having lunch in English, meetings in English etc. It is the international research language. So living there, working there for decades, certainly doesn't mean you are living and working in a Japanese language environment. Going the other way, a prof. like Michiko Yusa, who has lived in the U.S. for several decades has native level English. She worked damned hard for it, but also her day-to-day environment/life has been predominantly an English one. Foreign professors who are at native level in Japanese are just so rare because 1. Foreign professors are rare. 2. Those who do exist are often teaching/researching in English.