Look at prints, not megapixels.
The truth is in the print; what looks good on the screen doesn’t necessary hold in print (and vice versa). Having gone through the first set of cartridges and pile of paper, I am glad that I haven’t deleted my original files. In a number of cases I had to return to the RAW files and process them with adjusted settings. Let me explain:
Bryce canyon at dawn (seen from sunset point). One of my best-printing images. Linhof Technika 4×5, Fujichrome Provia 100. Scanned by MSP Graphic Services, Cotati, CA, on a Dainippon Screen drum scanner. 160 MP, corresponding to 15.7 x 19.6″ at 720 dpi, 16 bit, 920 MB tiff. Down-sampled to 2200 pixels on the narrow side and badly jpeg compressed to arrive at a 1.4 MB file size for web upload.
A widespread myth of sensor resolution (or the end of the megapixel race) states that if you print larger, you will step back further and, consequently, will never need the resolution given by higher megapixel cameras and prints. This myopic view of megapixels is correct if you are thinking of snapshots, looking solely at web uploads, or preventing* people from getting close enough to inspect the images.
* Helmut Newton’s big nudes are hung above the stairs in the lobby of the Berlin Museum, where it is physically impossible to get closer than about 2 meters, to realize that they are really not that sharp.