After completing the sound-deadening on the drivers door, I took some SPL readings in both the driver and passenger side foot-wells:
In the above, new data sets are in purple(passenger side) and green (drivers side). I was pleased to see that the passenger-side data (purple) aligns with the baseline (red) set taken before any work began.
Comparing the deadened door with the stock door, there is a -4dB drop from 5k-15kHz and about -8dB drop from 15k-40kHz!
Remember that this data may not be a perfect representation of all road surfaces, wind/weather conditions etc, not to mention the use of an iphone of this test! Regardless, I'm happy with the result so far and will continue the work.
As I had previously mentioned, I will continue the write-up for the passenger door as soon as it stops raining..