Re the smoother color comment: Many of us have said for quite some time that the Dalsa chip shows smoother color. In my test of a pre-release P65+ it could definitely be noted, but to my eyes it is a very subtle difference over the P45+ and perhaps a bit more over the P25+; like comparing the differences between Crystal and DP or Szechwan and Mandarin versions of Kung-Pao chicken, and to my palette not even as significant as the difference between Coke and Pepsi... Moreover, by adjusting the Color NR and/or the Clarity sliders in C1 you can pretty much make each file look like the other one, save for a more distinct difference in color response (profile).
Re the broader DR comment: We saw this in our comparison too, and it amounted to approximately 1/3rd stop more than the P45+ which was better than the P25+ by perhaps another 1/3rd stop. Ironically, when you adjusted the Clarity slider to get inter-pixel contrasts to match, the DR differences between these three backs disappeared to where they are for all intents and purposes, identical...
So while you can see these differences, they will likely only be noted by experienced digital file processors, possibly be noted by experienced viewers when comparing prints side-by-side, and probably not significant enough to be noted by 98% of the viewing public when not being compared side-by-side. (And it is interesting to then balance the p45+/P65+ justification comments against the P345+/G10 real-world print difference comments )
Frankly -- and I step way out on a limb here -- I think the stated differences are subtleties used by folks to create enough of a threshold of additional benefits to seal the rationalization for making their purchase. Don't get me wrong here, the P65+ is a remarkable achievement, and is the pinnacle of DB development IMO, and represents the best of what's currently available and IMO that in and of itself should be enough rationalization.