I agree, you don't want 25ms of latency introduced into your audio. I play a fair bit of fps online multiplayer gaming and sound is the first cue that you're being shot at, and our human reaction speed is faster to auditory stimulus than it is to visual stimulus - so audio will give you that edge in a quick reaction scenario. 25ms is too much. A quick Google reveals 140-160ms reaction time for humans to auditory, so adding another 25ms delay to that is increasing reaction time by about 17%. As a slight comparison to High Refresh Rate gaming monitors, if you're running 240Hz/240fps then your game & monitor is updating with new information every 4ms - so during that 25ms auditory delay your game engine and monitor has already updated itself 6 times with new information, so there's enough resolution in the "pipeline" to allow for a reaction speed difference of 25ms related to the audio delay to "matter or make a difference".
Certainly not as crucial as running 240fps on a 240Hz gaming monitor for instance, in terms of the benefits, but that's more about lowering motion blur (& receiving more fine grained visual information) than just video latency, but it is still a part (video latency). Audio latency of 25ms is certainly not desirable, and is a negative. I wouldn't buy this item based on that, not for competitive & not for "competitive for fun" fps gaming. I almost voted this headphone "Poor" because of this, but then I thought about the non-competitive side of things.