I definitely believe it. The beams on my 85mw 520 and my 740mw 445 look almost the same, brightness wise. The dot on the 520 is probably actually brighter.
That makes sense. Blue wavelengths scatter more easily than green, hence why the sky is blue. That explains why the beams appear the same brightness and the dots don't.
Scattering is one part of it, but it also has to do with how your eyes perceive the brightness of certain colors. Take a look at this table to understand how your eyes will perceive the brightness of a light source as a function of wavelength. here: Luminous Efficacy
You can compare different wavelengths of same or different output power with this tool programed by an LPF member rhd in 2011. t uses CIE table values. Raleigh Scattering is factored in if you choose "beam". here: Relative Laser Beam Brightness Calculator: (532nm 1000mw) vs. (445nm 1000mw)
Thread about it is here: http://laserpointerforums.com/f44/new-tool-calculate-relative-brightness-wavelengths-nm-61238.html