Well, yes, of course i can set the WB in post-processing as long as i include the Whibal card in my shots. And setting the Camera Custom WB still works fine even if the colors on the LCD are off.
However, i'm a painter and i often use the camera to photograph my paintings, for which accurate white balance is important. It would be nice to confirm that i have the correct WB just by looking at the camera LCD, instead of assuming it's right (even though i know that it can be corrected later) -- there's something assuring about seeing an accurate representation of the colors on the LCD.
BTW, the screen on my A570 is more accurate -- i mean, it may not be perfectly calibrated, but it hasn't made me suspect if it was "off" either. I find it funny that Canon gets it somewhat right on a cheap PS camera, but not on a DSLR
So, not a big issue, but it would be nice if it's somehow possible to calibrate it.
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