I am thinking about having my TV professionally calibrated but have the following concerns. I post them here because I bet there are a lot of people in the same boat with some of the same questions/concerns and I would be very interested in what some of the pros have to say.

1) My biggest fear is that I won't be able to tell the difference, or god forbid, find the PQ to be worse. I think I am a *reasonably* seasoned viewer but there are plenty of occasions when I look read complaints about PQ on this forum that I don't ever think my eyes would ever be able to pick out.

2) Our power has gone out several times this year. I have a 7178W. Is there a chance that the all of the settings will be eliminated (some of the things in the my settings have changed after outtages)

3) My components are a moving target (as I suspect is the case of many here with a similiar "upgraditis"). If I get the TV calibrated for my cable signal I might feel "stuck" with cable as opposed to dish etc. My cable signal isn't great. Can a calibration improve this?

4) How often to TVs need to get recalibrated? Why do they need to be recalibrated? I can probably swing a calibration, but if this needs to be done once every three years, that would be tough.

thanks in advance for any replies

On item 1, if you've never adjusted the brightness and contrast on your TV, then there will be a clear difference. If you have used the simple calibration DVDs and set your TV that way, the difference will be more subtle. I had already spent a decent amount of time setting my SXRD to what seemed most realistic, so calibration was like switching to a new color mode (ex. cool, neutral, warm). Without a doubt the colors are different from what was available in the original options, and it is noticable but certainly not dramatic. Like you I'm not overly critical about picture quality, for instance I've certainly never noticed CUE which seems to be a repeated topic here, but I have no regrets for having paid for what seems like more realistic colors. If you think cool, neutral, and warm look equally good, then I'd suggest passing and stick with a setup disk.

1) My biggest fear is that I won't be able to tell the difference, or god forbid, find the PQ to be worse. I think I am a *reasonably* seasoned viewer but there are plenty of occasions when I look read complaints about PQ on this forum that I don't ever think my eyes would ever be able to pick out.
If you're unsure about how your set might look after calibration, try to find someone who's TV has been professionally calibrated and check it out. Not everyone likes an accurate image. Bear in mind, it can take up to 2 weeks for you to adjust to an accurate display, especially if you're accustomed to the typical too-blue too-bright TV.

2) Our power has gone out several times this year. I have a 7178W. Is there a chance that the all of the settings will be eliminated (some of the things in the my settings have changed after outtages)
I for some reason, the new settings get hosed (a power outage would not cause this), the calibrator can come re-enter them. I offer this to all my clients. Usually, it takes some form of factory service to hose a calibration.

3) My components are a moving target (as I suspect is the case of many here with a similiar "upgraditis"). If I get the TV calibrated for my cable signal I might feel "stuck" with cable as opposed to dish etc. My cable signal isn't great. Can a calibration improve this?
A calibration can improve cable or satellite image quality to varying degrees. HD quality will certainly be improved. SD quality may not be. Calibration makes the biggest difference with DVD sources. A calibrator can usually recommend the best broadcast source in your area and the best equipment to use.

4) How often to TVs need to get recalibrated? Why do they need to be recalibrated? I can probably swing a calibration, but if this needs to be done once every three years, that would be tough.
With your TV (Samsung DLP?), you would need a re-calibration when you change bulbs. Most calibrators don't charge their full fee for this since they aren't starting from scratch.