I had my spark plugs changed last week,...first time since i bought the car in Sept. The spark plugs that came out were autolite and looked exactly like the ones in the picture ie. "burn" marks around the tip.
I had NGK BKR6E put in and the car mas not missed a beat since (was missing pretty badly before the change)
Good luck, but yes, i highly recommend the BKR6E for stock - mildly moded skylines!