I was one of the original people to review the 4.A and I stand by my comments. Can I write a better review now than I did then, which would maybe uncover more truth? Yes, but that's always the case many months or years after writing a review. One gains more perspective, more experience, logs more hours with the product, hears more competing models, etc. But I still maintain my 4.A sounds the way I described it, though I can't speak for anyone else's 4.A since each one is potentially a bit different. I heard the 4.Ai much later and could definitely hear the differences - rather significant ones. I liked the 4.Ai for what it was but always recommended the "real" custom version for a significantly improved experience. As did Sinocelt who was one of the earliest 4.A users/fans that I can remember.
I don't know about all this talk of being "misled" and reviews coming from "amateurs" and therefore not being reliable. Think about it - is anyone, ever going to line up completely with your preferences? Be it myself or Tyll or Average Joe or ljokerl or ClieOS or any other experienced listener - we all hear differently, and there's always going to be some product where you disagree with our assessment. We might even match your opinion 9 out of 10 times, but then comes that last one where we "midlead" you. Plus there are countless other users who may give their opinions - it all has to be taken into account, but ultimately nobody can "hear" the product for you - you have to try it yourself and see how you like it. Sometimes it works out, sometimes not. With CIEMs it is a gamble - no way around that.
This forum has a classified section through which I'd say every single headphone has passed at one time or another. Sony R10, Sennheiser HE-90, K10000, SR-007 and SR-009, Heir 8.A, JH13 and JH16, SA5000, all the top Grados and Audio Technicas and Ultrasones.... Sure, people don't usually come right out and say "I hated this headphone and now I'm selling it!" but short of a financial hardship, people wouldn't be selling if they truly loved the headphone. Does that mean everyone is being misled? Of course not. I personally hated the Sony SA5000 and find it bright, thin, and abrasive. I know people for whom it is "just right". I personally really enjoyed the Audio Technica W3000 but I know people who found it overly bassy with strange mids. And I get why they feel that way. We could go on about each headphone and why some people would disagree, or we can just say everyone literally hears differently and also has different preferences, and then move on. This is a hobby, remember?