I'm surprised that he felt that metamerism was such a big issue with ABW. What paper is he printing on? I've had another look at the prints and I guess the ABW does change a little more under different light sources than the QTR print. However I still think that the ABW print is closer to neutral and so any significant
change in the lighting source impacts more on how the print is perceived
than a slightly warm print. I didn't feel that this was really metamerism as I understand it. Perhaps I'm not discerning enough. He may find the QTR one too warm, but this is something that can be tweaked. I looked under a loupe at both prints, and it's hard to see traces of the colour dots in either. I'd be interested to hear what he finally decides and why.