If the TV is in its default mode, or the person has done nothing more than say switching to standard mode, then yes, you will very likely see a noticeable difference. See the comments in the last few pages of the following thread.
57's Home Theatre Optimization
This obviously relates to more than simply optimizing the TV settings, but it really depends on what you want done and who's doing it. After doing several hundred of these optimizations, I don't recall anyone regretting having me over. I'm sorry I can't really help you since you're in Vancouver.
With all the components going through the AVR, there may be a bit of a compromize in the settings, or you could calibrate several different picture modes if the components are different enough to require that. A harmony remote could then be used to do the switching of the modes automatically. Most people don't bother with this as the "compromize" is usually fine.
What's important in the optimization process is things like:
- the correct colour temperature
- the correct picture mode which allows for the most tweaking (some picture modes have options greyed out, or the functionality is done in the background and cannot be modified)
- an understanding of what the various items do - edge enhancements, sharpness, etc.
- turning off or turning down the settings that harm the picture quality.
(I deleted your other post since I already answered here)