One game things will hit and people react with human reaction times.
The next game with no noticeable difference in situation that should matter shots don’t hit and the reaction times of players feel superhuman.
People slide out from corners and you are just insta-dead.
You peek and you just slide right into a bullet before you can tell they are holding the angle.
It feels like the game isn’t properly checking client sync over a length of time and it just frustrating playing on an engine that feels busted.
The HL1 engine (aka QuakeII engine) always felt good and always felt the same; to me the Source engine NEVER feels the same :\