Okay, here are some of my thoughts on the game as it is now.
Graphics: RRRE runs very smooth on my system as it is but, any further gains in FPS might serve to reduce system heat although, it's not a major issue in my case.
Collision Model: What's that? I try not to use it
FFB: While our approaches to achieving the best feel may differ wildly, I think that RRRE's FFB is really great - especially where front tire grip loss is concerned and the way I can feel the weight of the car. My only real issue with it is what it took in terms of settings within the Wheel Software to get it to feel that way. It requires a radically different setup in the Logitech pro-filer than that from any other game. That will leave many people with a poor opinion of the FFB and physics in RRRE unless they spend a lot of time and effort to find that perfect setup. There needs to be a better default game FFB profile/setup for those using the Logitech wheels.
Car Setup: I agree with Andi, additional settings and save feature is badly needed.
In-Car: The only additions I would like here are to have "Look to Turn" and " Helmet View" option, yes - I know that I can wear a real helmet but, I prefer not to. It's one of the things that I really like about Shift2 and Pcars driving views. Yes, I know that makes me unusual, one-in-a-million, etc.
Sound: What can I say, I'm obviously a very aural person. I think that RRRE has started a kind-of sound revolution of sorts in terms of raising the bar in replay sounds. IMO, iRacing has already raised the bar another notch beyond by increasing the volume and raspy exhaust noise during departure where the cars have the new exterior sound samples. The results are very convincing - especially where the reverb is very noticeable, such as pit-lane. Pcars is making some good progress in this area and AC is said to have new code to support similar features with impressive downshift/backfire sound improvements. RRRE is very good but, may be falling behind now that the other titles are addressing the replay sounds and hopefully, these can be improved even more in the future.
Some of the interior/exterior engine samples could be improved as well, particularly the BMW Z4. The Z4 engine samples also tend to have a little noticeable looping. Overall, I like the gearbox sounds. The McLaren exterior sound suffers from some whispy intake or compression noise that is out of balance and can be heard from far away but, the exhaust sound is good. I think that the amount of gear-wobble could be increased in some cars.
More options to adjust the track-side sounds to our liking would be nice.
Tracks: Distance markers, personally - I kind of like the color coded system as it is but, I also understand the point of those that would rather have them more realistic. Ideally, the option to choose would be great. Another immersion killing aspect is that of off-track rhythmic bouncing that occurs when one ventures onto the path less traveled. It's just too consistent, there needs to be more randomness and variation to the bumps - I know, getting picky here.
Visuals: I think its in the works (driving moods?) but, the inclusion of varied lighting scenarios would be welcomed to provide more variety in racing conditions.
Thank you Andi, for asking for our input. I hope some of it is useful.