Is it game Mode only? Or can I manually disable it. I have mine on Vivid.
"Game Mode" and the "Game" picture setting are two different things.
The "Game" picture setting that automatically adjusts things like brightness, sharpness, tint, contrast, and other picture settings, is for sporting events, not video games, like "Movie" is supposed to be a good starting point for those setting for watching a movie, and "Vivid" is supposed to be a good starting point for those settings for watching in a bright environment (if I'm remembering the description for the setting properly), that has nothing to do with "Game Mode" which has to do with turning extra processing off so that it doesn't interfere with performance when playing video games.
R.I.P. Eve English (Feb. 12, 1968 - Oct. 13, 2010) Momma Eve, you will be missed.
If you have a high end HDTV, even with the extra processing, the lag is barely noticeable. Like for instance, I have a Bravia HX850 (with X-Reality Pro processor) and I have less than 10ms latency with effects turned on. It has never been a problem in any game I play and it is amazing with smoothing out Xbox frame rates.