Last I looked there was no translation between Montage Classic and any of the M models.  Soundmondo would be an incredibly inefficient way to do this since you would have to one-by-one upload then download every Performance.

Also, this may not apply to your Performances, but Soundmondo does not support user waveforms (custom samples) or even user curves, user microtonal scaling, or user arpeggios, among other user data.  The only user data Soundmondo accepts are the settings (parameters) within a Performance but none of the "outside" data.

MODX M does support direct loading of files from your Montage.   

Title

MONTAGE M: Can data for MONTAGE, MODX + , and MODX be used?

Description

”MONTAGE M” supports using ”MONTAGE”, ”MODX+”, and ”MODX” data.
The following types of data can be used.

• ”MONTAGE” (”OS v 3.5” or later)
  Backup files (”.X7A”), user files (”.X7U”), and library files (”.X7L”)
• ”MODX+” and ”MODX” (”OS v 2.5” or later)
  Backup files (”.X8A”), user files (”.X8U”), and library files (”.X8L”)

URL Name

000025632

... the above is from a FAQ covering the Montage M capabilities and MODX M has a more unified file system this go around so all of the above would apply to MODX M as well.  So, I would (instead of bothering with Soundmondo):

1) Ensure my Montage (classic) is updated to at least OS 3.5

2) Once updated, make a backup (save an X7A backup file)

3) Load this backup file directly into the MODX M

Be aware that this will erase everything that's user or library data already in your MODX M so if you want to save anything already on the MODX M then I would save it to a library file so you can load this as a library and this can be used as a basis to merge in the existing data.  Using library import (to the user area) if you would want these to continue to be edited.  

Since your MODX M is a future thing, I wouldn't worry about backing anything up since I would do the loading of my Montage content as the very first step after unboxing.  Or maybe update MODX M's firmware first if the firmware is not current then load the X7A file.

After doing so, your MODX M will be "identical" to your Montage in terms of custom content.

Yes - the Modx M can load Montage user or backup files directly.

1. Keep your montage until you have verified that the Modx m load has been successful

2. Make a user or backup file from your Montage to a USB thumb drive

3. Load the user/backup file from the thumb drive to the modx m.

4. If you don't have a USB drive that you know works make sure you format and test it on the instrument. Not all thumb drives are compatible.

Thank you guys for your answers, I'll let you know how it worked soon, have a nice day !

So I made a backup and user file on an USB stick, then went to my favorite kb store Espace Claviers in Bordeaux to make a test….. Worked perfectly, could load the files in their MODX M in a few minutes and all my performances were here !

Thanks again for your help !