I tried using it but I couldn't:
DirectX error: file d3d9_23.dll not found (something like that)
Then I tried it again a few hours later, and it worked
And is still working, it's working perfectly and very smooth... In Windows XP the fps limiter quite didn't limit the fps correctly (I put to limit the fps to 90fps and it limits on 84 or something, always below the fps I set it to and so on).
In Windows 7 when I limit it to 90fps it gets a INCREDIBLY STABLE 90.9fps! after driving 4 full laps the fps didn't change anything at all, just like it was stuck at this number
...
Game runs smoother too, more fps overall (without limiters), and more fps when using ENBSeries in LFS too. Everything is soooo much better now
And by the way, for the first time since I bought it, my LFS locked to demo again. Never happened before, but it looks like this was supposed to happen so no problem at all here