I've gotten more shift out of them than Zeiss says is possible. Here's my experience (on 6x6 film with a Flexbody; on a 48mm x 36mm sensor, you get a lot more shift, especially if you're shifting in a direction perpendicular to the sensor's orientation):
40mm CFE: 2-3mm
50mm CFi: 7-8mm; at 10mm, light vignetting is visible
60mm & 80mm: 12-13mm; at 15mm, light vignetting is visible
120mm: 15mm
As mentioned, this is at infinity. It also helps to remove the lens hood (which starts to appear in the frame at the limits of shift).
The shift available increases dramatically when using a smaller sensor, as described above. I've gotten a full 15mm vertical shift out of the 40mm, with a 48x36 sensor positioned horizontally. I coudn't see any vignetting at the edge (bearing in mind that the edge was part of a room, and not a clean area like a blue sky).
ethan pines