Few things I don't understand. From his original review
http://web.mac.com/kamberm/Leica_M8_Field_Test,_Iraq/Page_1.html he had a laundry list of dislikes about the M8. I'm having a hard time seeing where the M9 specifically has solved many of them. My comments are in parentheses.
1. Framelines set too loose (the M8.2 tightened them, but M9's are only about half as improved as those.)
2. Rear buttons not recessed (hasn't changed on the M9)
3. Exposure compensation setting (improved, starting on the M8.2)
4. Poor AWB (improved with firmware on the M8)
5. Autoexposure unreliable (same metering on the M9)
6. In Manual mode, shutter speeds not shown in finder (same on M9)
7. Low light capability (improved on M9, but still not quite to the level of the Canons he was comparing to, and the new Canons have improved more)
8. No fast wide lenses (Leica since released the 21 and 24 Summiluxes, at the time he wrote these were "only" f/2.8)
9. Buffer sluggishness/write speed (still a complaint with the M9)
10. Cost of replacing filters. (Improved because now he only needs to replace UV filters every six months, not UV-IR)
9. Lack of DOF (frankly I don't get it, because I just don't see a huge difference in DOF between the same framing of the same subject using a 21mm on my M8 and a 28mm on my 5D which give the same FOV)
I'm glad he's happy with the M9, but it seems to me most of what he found so objectionable about the M8 is still true of the M9.