I dob't know how other HL2 players feel, but I am getting very frustrated by the implentation of the physics in Sin. The biggest problem is what happens when a gamer tries to release an object. The durn thing flys through the air in fairly random ways.
Also, there are times in the game when you should be able to climb over a fence with the help of some barrels or some such, and the game just does'nt allow you to step over it, even though you are high enough. Alother situation is when the trucks carrying enemy soldiers stop in the fence gates. You should be able to climb over them, but you can'.t
This all make the game a little hard to enjoy, because one doesn't know if it is the game or the player which is failing any given challenge.