VT30 have oversaturation bug in both PROF modes (ISF Day / Night - in US).
Faces, bodyes partialy looks too red. US and EU models - no difference. THX - have not.
Its very hard fix by calibration. So - calibration of this model and seeing in ISF-mode maybe some sort of worsening picture pleasure.
This problem discuss in VT30 calibration thread (HDJ forum, "Official Panasonic TC-PXXVT30 Calibration Discussion", page 6).
"Have now calibrated 12 VT30 panels... I will say this chassis is the most difficult display to correctly calibrate that I have come across in many many years" - Kevin Miller.
"After doing a couple more, I am more frustrated than ever with at least 3 things in the ISF modes (and Custom): improper interaction between the calibration adjustments, aggressive / unstable ABL, and color decoding issues.
There are ways to minimize the issues, but are they worth it?
The easiest and possibly best thing to do for many calibrators would be to calibrate THX mode for a day mode and Cinema for a night mode" - ChadB about 65VT30.
Ha-Ha! Calibrate THX? And not to leave to the TV owner possibility to compare?
P.S.
Panny VT30 THX-mode also have troubles. Average color temp too warm - around 6200K (ref - 6504K).
There is no red push. But is yellowpush.
For example - "Quantum of Solace" movie.
In some air scenes Bond girl`s skin - seems too yellow.
And see scene - 43 min 58 sec. THX demonstrate uncanny yellow spot on face.
P.P.S.
About "calibration wow-factor" and THX/ISF difference.
1) Take MacBookPRO
2) Do calibration its screen by any good, but cheap meter like i1D2 ($150).
3) Its do good adjustment. And MacBookPro matrix color space -> 1:1 = sRGB (same as rec709 - Blurays). No distortion.
4) Go on.
Try to establish on the Mac screen the same brightness that on the TV screen.
Start the same bluray movie on the computer and on the TV.
Stop the most pleasant shot.
And change in menu: ISF - THX. THX - ISF...
5) So. Do you see any significant difference? Between Mac screen and THX? Between THX and ISF? Mac and ISF?