The Vizio website says that the V-series has a full-array backlight. This article says it does not. It says that last year’s model also has a full-array backlight. Did you get your specs correct?
Hey there!
Since this isn’t something we tested on this TV, I can’t say for sure what kind of impact it has. Generally speaking though, since input lag adds processing, we do expect it to have at least some impact on input lag. However, it shouldn’t add a very noticeable amount of lag. So, if it isn’t something you’re particularly sensitive to, then you can probably get away with enabling local dimming without any issues. Worst case scenario, if it bothers you, simply turn it back off!