First off, having a service contract from Sears, CC, BB, etc. for a yearly cleaning, convergence does not constitute a calibration. When you get your set ISF calibrated it is a long and thorough process. Full geometry is done as well as all inputs are calibrated. Service menus are tweaked, grayscale is set, guns are focused, etc, etc. My 57s700 took nearly 6 hours to do by a real professional and the results were night and day. So is it worth it? IMO, yes. Would I let a so call "technician" from Sears, BB near my TV? You got to be kidding? LOL. Also, be prepared to spend $500 min for a full ISF calibration.