"...are we there yet?" ;-)
Never used Noise Ninja, but just looked at it on the net and reckon manualy adjusting the overlay properies of bracketed exposures would be more "artistic";-) Top tip: When scanning photos with a cheap flatbed scanner to remove permanent marks on the scanner bed do two scans, the second very slightly diagonaly moved across the scanner bed. Combine and align the two scans using the 2nd as an overlay on the 1st. Align using 50% transparency, return to fully opaque then blend if darker/lighter or such-like. Similar principles can be used to remove crowds of people etc from landscapes/interiors. Practice by downloading sattelite photos from the MODIS archives and removing the clouds.