Do remember that Spain is a very differently built truck too,
As far as I knew, the clutch was DMF in all d40's.
They just seemed to get better lately,
SMF
i am pretty sure there is no D40 with SMF as standard fitted so you probably are mistaken or drove a bad spanish d40.
SMF a lot noisier? you barely notice it in idle. the only thing you will feel with a SMF is vibration if you drop under 1,000 rpms which is just absorbed with the DMF. also when you depress the clutch too quick when changing gear you will feel that knock much more with a SMF because the DMF will just absorve it.
is a lot noisier and built for off road work etc, where DMF is the soccer mum friendly version for a 4wd.
I could be wrong,
Mine is a 2011 st Thai built and my clutch lasted 60,000 no towing very little off road used