I played LeMans yesterday too, and it definitely looked great ! I play with rain so much now, I love it. I also don't know if I nailed rain tires in my cars, or if it is just that visuals makes such a difference for driving sense too
Some of the improvements are global, I raced Le Grands Circuit mod as well, and obviously it also benefits of many of improvements. I can't get enough of shadows appearing and disappearing regarding lighting type, onboard autoexposure, godrays and SSR in the rain, it does a lot to me. Appearance of tracks drying and racing lines is so much more organic now too.
Yes unfortunately there are all sorts of quality levels across. But IMO it is better than having nothing. All that matters is that all official content would be updated, it would also be a beneficial for it to be highlighted, excluded from the rest. rF2 already has this functionality of "All tracks, all cars" and so... it would be nice to have content grouped in "folders" fashion and separated for tracks and cars. Official cars, official tracks, mod cars, mod tracks, and then perhaps even get make it possible to do custom folders. Would be great to have small pre-launcher to choose it, perhaps bring back such comfy way to launch dev mode too. IIRIC not launching "all cars all tracks" makes new UI a lot faster to open, otherwise it is painfully slow sometimes, painfully.