Many of us old timers call them NEVER ready cases. I have not used one for at least 35 years, and never had a problem with the camera because of that. I have often bought and used wider camera straps, such as the Optex foam ones, but I don't want to have to flip and flop a case to run the camera.
With your MX, to change film with the case on, you have to
- Remove the camera from the tripod, if it is on one
- Remove the never ready case top
- Remove the tripod hold screw and the case bottom
- Rewind the film
- Open the camera back
- Remove the film
- Put in the new film and close the back
- Mount the case back on the camera with the tripod screw
- Attach the top of the case
- Remount the camera on the tripod
Steps 2, 3, 8 and 9 are added by the case.
An old ****'s opinion.