I'ts a weird issue, and i'm sure it has something to do with the specific hardware combo, but it does sometimes happen. it definately fixed my witcher 3 issue i was having which was causing extreme frame loss down to 20-30 when mouse turning from 60 fps. also i didnt see any drops like that in bf4 and i was getting big drops in bf4 when mouse turning also... this guy had a similar issue on planetside 2. I mean it does make sense kinda. depending on the CPU. higher polling rate is gonna have more CPU usage. I don't think i'm good enough to really notice the input lag difference, and my k/d has gone up since i'm not stuttering down to 20 fps when aiming lol.
https://www.youtube.com/watch?v=3q9hzfs5V5c
check out this guys video also
125 hz vs 1000 hz about doubled his cpu usage percentage. that may be what causes it