I used these often back in the day, in a studio, to shoot beauty and fashion. They are SLOW (think 5 seconds between shots), shoot tethered only, but produce beautiful files. Check out tis site:
www.sarasilver.com. Look at her early beauty work. Not sure what Sara shoots today, but back in the day ut was a 54M on a 503CW Blad, tethered to a G4 Powerbook, running lightroom and Capture shop. The low prices reflect the (lack of) speed, no LCD, tethered only operation, not the IQ. I switched to Leaf and Phase before exiting the MFDB market, but only because I like to shoot handheld with a screen.
The 54M files are as flexible as the Aptus 22 and P25 files in terms of range and post. ISO is better on the Aptus, and the P25+ is a different generation. The Phase H25 is closer in terms of post, but I found the 54M files to be MUCH better (subjective, I know) in terms of color.
Good luck with this.