Hi Pyramid,
I'm another happy J owner. My J faces up very white in about 90% of lighting situations. In one restaurant with coppery interior and low candlelight, my stone returns yellowish light. That's the only time I notice it looking tinted, and I stare at my diamond ALL THE TIME.
More importantly, I think one can make a distinction between the ranking of clarity grades and color grades:
-Visual performance: Flawless through SI, generally, the differences between grades are not eye-visible and don't impact the visual performance of the stone. However, with color grades, that's not the case. People with sharp color sensitivity can truly see the difference between stones of 2 (or even 1) color grades apart.
-Personal preference: I have yet to meet someone who prefers the look of cloudy, black carbon-spotted diamonds to the look of clean ones! (Well, except for those few sentimental posters who have grown fond of the lone "birthmark" on their stone!) However, many people actually do prefer the "warmth" of H-J color diamonds, as opposed to icy white. A friend of mine has always been turned off by the "coldness" of diamonds, but liked the look of my J set in yellow gold, because to her it was more inviting.
You may have seen many stones already, but on your next shopping trip, maybe you can focus on comparing color grades, and see what you personally like. For me, I felt like I was getting a great deal by going to a perfectly cut J color stone--I got a bigger stone within our budget that way.
Does that help at all?