I think LFS has some of the best sim graphics "out of the box" so to speak, and when racing you don't need to see every fleck and speck on the track or tiny detail of the dashboard.
The only reason I would consider installing any non standard textures would be for movie making.
Nathan has brought up a good point about HW specs, when reading about FPS probs in the tech support section many users neglect to mention they installed a load of mods into the game, and then wonder why they get FPS or other issues.
Also as this thread shows, it can get very confusing with the amount of texmods available, just looking at the 7 links posted above, while they all look great, I can't help thinking people will try to install everything, and end up with a mix match of stuff that is just slowing down both loading time, and fps.
If you like to watch replays a lot or are into movie making thats totally fine, LFSNoob and others here can give great info on whats best ITO, however if you like LFS for the great online racing and maybe don't know the limitations of your HW then the "vanilla" LFS is way better than most sims and more importantly plays best as it is.
SD.