Here is what information about 2.60 and 2.55
2.60 is for scriming (most of the times)
thats becuz the hits are a little bit more fair,
at 2.55 something if you got your cursor on the enemy and you dont hear a shot , thats becuz some server in 2.55 are polish or something and then you get unhit,
at 2.60 (2.60b) is that fixed thats why they play there scrims.
I hope you enjoy my information and understand it