We disagree about the sound. As for graphics, I'm mostly curious about seeing something that supports your ongoing claims about additional objects and shrinking. This time you started out by saying you'll take comparison shots, so I don't know why you're now talking to me about it being time consuming. It's up to you, but it would be cool if you can find the time to make a good comparison. Anyway, people say this discussion beats a dead horse... If any of you have a link to any previous conclusions to it, please provide a link if possible.
About my audio setup, it's something like what you described.
You previously mentioned the background scenery at Catalunya, so I looked up a gameplay video on YouTube. The background scenery looks a little more detailed in FM5, but the the size of the mountains beyond the Catalunya main straight appears exaggerated compared to real life. FM6 got them more true to life at least.
@Maxx2013 mentioned "better" windshield reflections in FM5. I think those too looked exaggerated in FM5, much like the almost blinding sunlight glare. Thinking about it, exaggeration may sum up why FM5 never appealed to me, whether we're talking vicious sound or eye candy defeating the purpose of being the "realistic simulation" Forza Motorsport identifies with. Don't forget that FM6 added graphical touches spicing up the overall atmosphere on tracks, so it's not all compromises to accommodate more cars, frames, calculations, etc.