Full-frame M-mount buying guide (opens in new tab)
drewhoover.com/m-mount-buying-guide
Every full-frame digital M-mount camera, M9 through M11, M EV1 and Pixii Max, on a timeline and in one table: CCD vs CMOS, usable ISO, shutter, screen, cards, sealing, close focus, reliability history, size, and what each sells for used at B&H, KEH and Adorama. Built because Leica's names (M-P, Typ 240, M-E, M-D, M10-R) hide which bodies actually differ.