I have written quite a bit about the HTC One, including my thoughts on why it is the best smartphone I have ever used. I urge you to now pull up a chair and spend a couple hours learning everything about the HTC One. The AnandTech review written by Brian Klug is epic, and I have never read a more educational and informative review of any smartphone in my lifetime.
Brian doesn't just cover the hardware and software, he goes into depth so far that I bet that many folks at HTC are even learning things about the HTC One from his review. I was impressed when Brian gave a presentation on optics at an event I attended, and I can guarantee you will learn something new from his review. It is really more of a thesis than a review, and will likely be remembered for years.
There are 17 pages in this review, hundreds of photos, and extreme analysis. No smartphone has been exposed to such detailed analysis, and the amazing thing is that in the end, Brian awarded the HTC One the Editor's Choice Gold Award, and he has never given a smartphone such an award before.
I feel even better about my Developer Edition purchase and agree with Brian's conclusion. Do not jump right to the conclusion though; read, study, and enjoy this epic review, and share it with others.