Michael, your update on the A900 is useful and insightful. However, with the introduction of the 5DII, I wonder whether the A900 really lives up to its potential.
From this update I take away the following about the A900 vs the competition:
- very good overall resolution and IQ, but
- relatively poor high ISO performance (over 400)
- no live view
- somewhat limited lens line
- inconsistent raw processing
- lower battery life
Michael you also mention that you appreciate the A900 because provides the resolution and image quality that it does without forcing one to have a very large camera body. Except that we now have the high resolution 5D Mark II that can handle a vertical grip too.
Also that he viewfinder is "the biggest and brightest that I've ever seen, and that includes the 1Ds MKIII",. Except that the 1Ds3 has a 100% field of view and a .76 magnification vs the A900's .74. The 5DII falls behind here with a 98% and .71 magnification.
Not to quibble with your conclusion as I agree the A900 is extraordinary value, but the decision that needs to be made is whether one should or should not spend an extra $1,000 for the 5DII and get a camera with better ISO range, slightly better overall IQ (in tests I have seen), vertical grip option, long life battery, live view, consistent raw processing, lighter weight and an extensive lens line. In my view, it is worth it but then I am biased I guess.