On the 747 the economy “comfort” seats just have a bit more leg room, but are the same width. So barely better than normal economy (and no different to an economy exit row seat).
At least the seats on the 747 are not the super narrow type they have fitted to the 777 (which is 10 across instead of the normal 9 across with most other carriers).
I used to fly klm a reasonable amount (and had platinum because of it). Now I have flown with them once in the past 3 years. Instead i’m flying with BA or LH about twice/month.