The differences between the Sinar X and P2 are:
1. The X has red shift knobs, while the P2 has black knobs.
2. The P2 has an easily removable frame on the rear standard, enabling changing the format from 4x5 to 5x7 or 8x10. The frame on the X can be removed only by removing the large screw below the focusing screen, so it is not easy to change formats.
The differences between the Sinar X and P2 are:
1. The X has red shift knobs, while the P2 has black knobs.
2. The P2 has an easily removable frame on the rear standard
I think the X also doesn't have detents for the 0 positions on the geared movements. The P series all have detents for the 0 positions so they can be set by "feel", and not just visually.