>Not saying that those 5 ms are important, if anything constant 25 ms is better than 20 ms with +5 ms spikes, but reaction times have very little to do with actually hitting the other player. But when you have server side hit detection the lag is really important.
Lag correction is key here.
Competitive CS is at a very high framerate(often around 120Hz). So at a 20ms ping, the client is around 2.4 frames behind the server. At 25ms, it's almost exactly 3 frames behind. That means that, on average, the client is going to be rendering 20% less lag corrected frames with the lower ping, which is a pretty huge amount for player movement.
Lag correction is key here.
Competitive CS is at a very high framerate(often around 120Hz). So at a 20ms ping, the client is around 2.4 frames behind the server. At 25ms, it's almost exactly 3 frames behind. That means that, on average, the client is going to be rendering 20% less lag corrected frames with the lower ping, which is a pretty huge amount for player movement.