I didn't say me owning one changed the outcome, I said I didn't notice it over a week of usage.
Coming from a 60Hz display, there's a clear difference between it and this display in Lightboost. The XL2720T may not be the best Lightboost display out there when speaking purely in terms of motion clarity but the motion clarity IS better than any other non-Lightboost display at 27".
In other words, for some of us, a single 24" display is not big enough, or 3 x 24" displays is simply not an option. The next best is this 27" display, which doesn't have the best Lightboost performance of all Lightboost displays across all screen sizes, but still has (much) better motion clarity than a non-Lightboost display.