Since I am too cheap to paid BG $25.00, I will just post here at LL.
I have up grade from my P25 to P45, at first I really did not want to do the up-grade, because of all the stories about the color cast on the P45. I really did try to get a Aptus 75 but the cost was too much. So, I up grade to the P45 because of the cost. When BG was free, someone was really mad at Phase One because he had color cast on his P45, I pm him and he told me that Phase One had switch backs with him and he was on his third back, with all of them with the same amount of color cast and that he did not get it with his P25.
This is my story, I finally did up grade my P25 to the P45. I did have a color cast problem with my P25, but it all depend on the subject matter, on how much color cast was in my image, but the LCC in C1 did correct the problem. When I got my P45, it has a weaker color cast then my P25, in fact alot of my images, I did not detect any color cast. I do shoot a lot of fine art images and one of the biggest problem, that produce a lot of color cast, is the dry lake bed in Vegas. Because it is light/medium tan color and I like to use my 35mm lens. It did produce a small amount of color cast but the LCC in C1 correct the problem.
So, I could see that some of the tester, will not mention the color cast, because maybe they got a selected back from Phase One and they never notice the color cast. I did not get one of those select back, I am just a average Joe that might of got lucky. Now I love the back.