I would venture to say that if you're looking at a calibration setting from, say the C|Net HDTV Picture Settings forum...
...the settings for one may produce similar results on the same-mode-different-sized unit. I wouldn't go as far to say identical, but would likely be similar to where a little extra fine-tuning would give you the picture you want.
Hope that helps.
Hey. Was looking into getting Samsung PN50B560 since CNET gave it a good rating, but found its little brother about $300 cheaper. Was wondering if there is much picture difference between the two. If there wasn't then was wondering what the picture calibrations would be for the 550. If anyone could help I would appreciate it. Thanks!