To me it feels that it is, I don't have any decibel numbers before vs after..Is the car quieter on the motorway? To me road roar through the tyres is the thing I would want to reduce, I wonder what effect doing the doors like this would have on that noise.
Before I finished, I drove a few days without door card and mounting plate (as on the photo above, without deadening, just with window motor hanging on cables), felt like the door was open. I think that a lot of noise comes through the door panels.
Next week I'll give a lift to a couple of passengers. I'll ask if they can feel the difference