Unsurprisingly the different M-climates associated with IFS and AIFS show some discrepancies.   Broadly there is a tendency:

• for upper tails of AIFS to be warmer than IFS In mid-latitudes.
• lower tails of AIFS to be colder than IFS in northern latitudes (e.g. Arctic Canada).

This implies AIFS M-climate has a larger range than IFS M-climate.  This  difference tends to generally increase with forecast lead time.

Broadly the AIFS M-climate range is closer to the range of the observation climate than IFS M-climate, (though this is not necessarily true everywhere). 

The differing behaviour (different biases) of AIFS M-climate and AIFS M-climate can be a problem for EFI.