I received my P30 and have had a few days to play with it so I thought I would post some first impressions to further confuse those who are mulling over a DB purchase. I am using it with a Mamiya 645AFDII.
1. First and foremost, the back is extremely easy to use. I am pretty much addicted to the control configuration of canon 5D and 1D Mk III but after 1 pass through the manual I had everything down. I thought the 4 buttons would require endless menus but the truth is, it is simple requiring just a few depressions to do anything.
2. Coming from the canon gear, the dynamic range of the P30 is really incredible. The best test I could think of was to shoot puffy clouds in the middle of the day. With the canon gear I almost always have to use HDR to get anything close to usable. With my first exposure on the P30 I checked the exposure warning and nothing. I thought I might have under exposed it, but the histogram looked right. Needless to say from the first shutter release I was sure I had made a good move. I expected more DR but I have to say, my first experience in the field really brought a smile to my face. I just finished reading Alain's book Mastering Landscape Photography and I think I will do his DR testing on both cameras.
Here is a 5D HDR using three exposures: