Ok I went ahead and tried it... In my opinion it's fine if used in minimum amounts, and with some things turned off (like that Sepia option, seriously wtf?). Still I need a lot of brightness applied on my monitor otherwise most maps look like Stalker with the ever-lasting dark atmosphere. Also looking at the sky can be painful, and bandages shine like Christmas lights.
Still I wouldn't recommend it as it says in the readme it might interfere with PB and I also noticed it reduces the bleeding effect a little (at least for me) thus providing you with a bit of unfair advantage).
Maybe I'll test it a bit more and then decide if I will stick with it on singleplayer.