Those comparisons take me back... I was a fan of the Xbox 360, and as most, I automatically would prefer Forza.
I was one day watching a comparison video between Forza4, GT5, and real-life. The video would switch between the platforms, sometimes showing them side by side, other times, fullscreen. I was in awe looking at the real-life footage, thinking to myself: it will take years before we have this level of graphics in videogames. Then the video switched again to the real-life footage, but with slightly more camera shake and a different tint. I was completely shocked. I was unknowingly marvelling at GT5's 'Ring thinking it was real-life. Afterwards I preferred not looking at comparison videos, as you might expect from an Xbox fan
When Forza 5 comparisons out, I remember thinking: finally! overall Forza 5 looks much better! But that was essentially comparing 256MB of RAM vs 8096MB of RAM, I was such a fool.
In retro perspective, what they did with GT on PS3 was nothing short of amazing. If Forza 7 came out in 2018 had half of GT5's 2010 features, fans would be in awe and regard it as the most amazing and complete Forza title ever. I realise that now.
With GT finally having audio to match it's graphics, it's going to be amazing for racing fans (who have PS4 that is, otherwise, not so much)