What I dispute is that professional calibration is a requirement for most Plasma and LCD HD TV's and has been greatly over hyped. Nor that the test equipment is needed unless there is something wrong with the set in the first place.
I have an issue with dead on accuracy being over-hyped, but oh well. I do have two issues, like yourself, and the first is a big one: cost. Otherwise, there isn't any other reason to argue against a top notch calibration. Right? The second is something that you addressed near the end of your post, finding the right person. (you don't own a Signature Pro panel right? What do you have? I guess can use search function too...)
My brother has a 50" 80u Costco equivalent. I would never consider recommending a pro cal to him, because that would represent over 30% of the costs. The OP has a Signature 141 for crying out loud! This represents an entirely different world of calibration flexibility! And cost!
The over all perception of the picture has a lot of factors well outside the control of the TV, the most significant being the ambient light level in the room, the direction of the light, and it goes all the way down to the color of the walls and even to a degree the color preception of the viewer.
All of which is adjusted for by calibration, except the last thing, which is extremely moot and pointless. I'm not going to present the argument here, but just ask that you think about it for a little bit. If the answer still escapes you, I can later oblige.
If you mostly or always watch in controled conditions that are as static as possible I might go for the pro calibration argument, but given that outside a Home Theater room designed as such or a movie theater that is something that applies to at best 1% of the TV buying public for their home.
Did you note that the 9G link above? There are reference suggestions for BOTH day and night viewing. The OP seems to have the propensity to forget a lot of what I say, and seems to prefer your recommendations that you kindly lay out, and so I'll just repeat what I've already said in one of his multiple threads:
The pro cal will get you specific calibrations for DAY and NIGHT settings for EACH source. That is a LOT of calibrations!
They in fact have significant changes in lighting, content, sources, etc that make prorfessional calibration IMHO typically a waste of money for most people.
It's a reference setting. After that, you can blame the software. I blame software all the time. But when the software is good, you've never seen anything that beautiful in your life.
Those things you can control with the user settings and a reasonable calibration disc are going to get most 98% or closer to anything a professional calibration is going to produce and without either, you are likely in the 90-95% range out of the box.
I would love if you can share your math on these results. A list of variables would be nice, with their weighting as well. Last time I was involved with the topic of pro cals, I actually said "half-way" there. Also note that I concurred with the particular recommendation of the person doing the calibration (which is related to our second issue).
Now factor in preference and perception and just as most people don't listen to music perfectly adjusted to studio standards, the horrors of it all they adjust the tone controls or on better sets the equalizer until they get the sound they like, and they may even change those settings based on content, mood, and many other very unscientific criteria.
Sure. But, that leads you to advise against a pro cal. Look, I've never once received a pro-cal. But I typically try to advise towards the ideal, in light of the OP's situation. After thousands of posts just at this subforum, this might very well be the very first time I would be even somewhat adamant about a pro cal. However, this is also the first time I'm involved in a thread about a 141 purchase!
My picture is no more inaccurate than an original Van Gogh, after all in the end it is what I like, not what some piece of test equipment said was right.
It is a given that subjective preference cannot be argued with. Duh.
However, even if you put that argument aside, the real issue still remains, calibration for the vast majority is a waste of money since it is calibrated to a standard in lighting when the cal guy is there and change in ambient lighting pretty much blows the finer edge off of that calibration except in very similar lighting.
Read above. Now if one PREFERS having ambient lighting for most viewing, than yeah, I would agree a videophile they are not. Save the money. Don't buy the 141!
The final issue I have with "professional" calibration is what most people are really getting for their money, some guy that went to a 3-day class, is armed with a check list of values for a given set, and test equipment to attain those values and that is all you get, which can still be far from an "accurate" picture.
Where did all of these calibration "pro's" come from? Granted there are real pro's out there but most are no more a real pro then the guys at the local tune up shop who were taught how to set a spark plug gap right, the real pro's are at the Indy track or drag strips with racing teams and a handful around for the general public, the rest are hooking a computer to your car and replacing your plugs, and making sure the computer is showing values from their rote sheets.
It takes a lot of experience as well as training to really be a pro and HD TV's have just not been out long enough to honestly say most who are doing calibration are "pros".
Your final point is extremely valid. But, helpful persons on forums can help guide those who want the best out of their systems.
Here are some more bonus links for whoever cares:
Display Calibration Subforum
ISF Calibrators, where are you located? Please post here!
Display Calibration: Root Fundamentals