TL;DR: PC players have a huge advantage over Mac players. PC games will see you before you can see them. + Some cool things about CSS
LERP is basically the buffer time hl2 engine uses to make gameplay over the internet "more consistent". Here are some following commands that can help your LAG issues or Reg Issues.
LERP: On mac its set to 100.00MS no matter what. What you want to have it at is between .015-.030.
Here are some commands to help: (= what pro players suggest / use)
cl_cmdrate 67 or 100
cl_updaterate 67 or 100
(cl_cmdrate/updaterate should be +1 the servers TIC [since the update tic rate is maxed at 66])
rate 45000-60000
cl_interp .015-.030 (only for PC)
cl_interp_ratio 2
FPS Help: In CSS you render all bullet wholes, ragdolls, ect. I personally don't wanna waste CPU power on dat shit.
r_decals 50
mp_decals 50
cl_ragdoll_enable 0 (unless you really want to see dead bodies on the ground :/ )
HDR + Bloom should be off
Don't use AA. Its an FPS killer.
Settings should be low-medium
Disable spray paints
If you care to edit your video settings more. Download a "autoexec.cfg" for source and see all the settings in it. You must add "-autoexec" to your launch commands.
Apparently on mac adding the commands +gl_nullqueries 1 +gl_bufmode 1 help out a bit also.
Tips + Tricks----------------------
Left Side of body is a smaller target than the right side. With a body peak around a flash corner with a sniper and line up the crosshair scope with the wall and you'll see what I'm talking about.
Higher Angle POV: If you jump and don't move you're POV will be raised. Really helpful to kill people while your head is over a box.
All pistols are as fast as your knife, the only thing faster is a scout.
Source recoil is always "random". Basically vertical recoil is about the same, but horizontal recoil will always be "random". They ever notice when you aim at their neck and tap with a m4/ak you miss? Its because its never fully consistent.
If you can turn around while a flash bang goes off near you, it minimizes the effects of the flashbang.
to see how recoil / your aim is. create a server, type sv_cheats 1 in console. Type sv_showimpacts 1. Wallah.
cl_dynamiccrosshair will always lie to you. don't use it.
to improve your aim just deathmatch.
Autosnipers will shoot with 95% accuracy in air.