Is that a DLP? Any rear projection set with a bulb for the backlighting should be used for at least 100 hours or so before ISF calibration, at least that seems to be the consensus from what I have read.
I would use the TV for a few hours a day for at least a week and then do the basic calibration using AVIA or DVE. Then only if you feel something is lacking, go for the ISF calibration.