Here's the issue with anything claiming to be better than rawinput... It's already "perfect". You can't possibly improve on anything that correctly processes the raw input because you can't possibly have any more information.
Any addon/mod/program that claims to be "better" has to get the mouse input from somewhere... and guess what: it's the raw input. So as long as the report from the mouse, say "move 100 counts right", reaches the game and it does exactly this, there's literally nothing to improve. The only issue is when this report does not reach or register with the game, which in CSGO is pretty much a non issue. A lot of games do struggle with this though, but CSGO is not one of them.
Also, any additional software between the mouse and the game will only add latency. While it might be insignificant it certainly outweighs the potential benefit of improving something that doesn't really have an issue.
Maybe there's some benefit to certain older hardware I'm not aware of, but if everything is up to speed this isn't something to even consider.
I don't think I can test the latency specifically other than by feel for now, but accuracy I can definitely test. So I will do this and see if there's any benefit in a real world environment. It would surprise me if it is, but I'll give it a go and eat my words if I'm wrong