Why do you think Raceroom with unreal-engine couldn't look like that?!? On that screens I can't see a single thing that the unreal-engine wouldn't be capable of... and that with ease...
The current screenshots of GTR3 / R3E with new game engine are more than disappointing and look more like some pics from a comic book in my opinion. These are far away from a realistic look in comparison to the DX11 Wreckfest game oder iRacing sim. I hope, I am mistaken and the new look of R3E will rock the sim market on day … Unreal is great engine for Games or Pixar Movies but not suitable for realistic Racing Sims:
Engine != Shading style. You can customize so much in unreal that different looks are possible. Post processing, shading models etc. The benefit of the engine lie in the management of all the systems, not that you don't have to modify anything. The point of the screenshots was showing that the content pipeline, getting the tracks in, works, arguably more important from technical standpoint. You can tweak the look after that. Which I am sure they will do.
The first pic that you've linked was a leaked very early screen of the transition to ue4 - so not a good example for your arguments. In your following pic you see the next step in working progress. But the UE4-pics that you've linked are still from a proof of concept that shows that an implementation in UE4 is possible and has not much todo with that what will come in the end. Most of the models used in that are 1:1-transitions from the current engine. Why do you think it is not suitable for realistic Sims? Do you have anything proven or are it just plain words to express your opinion? Why do you think sector3 and SimBin are going to UE4 when it seems to be impossible to create a RacingSim with it?!
Think kartkraft showed some good racing visuals in ue4. There are benefits to self-made engine like the other titles you mentioned, I am sure pcars2 is gonna be a feast for the eye, but if simbin/s3s had the resources to do that, they would have done that already. Ue4 is a reasonable !/$ option to them. Think reiza was also looking at ue4. Some developers clearly got more lucky to have very technical guys in their teams. But likewise simbin/s3s are good at atmosphere/immersion. Which is a great skill, too. I wish s3s had the resources to just upgrade to dx11 and incrementally improve their own tech stack. But apparently their budget doesn't allow that.
there are buttons under your monitor to manage it. try to use them, the screenshoots for me are pretty good and far away to be pixar movie honestly.