GT's very strong on the cars, and was ahead of the curve with replay cams. However, the scenery really breaks the illusion more often than not. While playing, it might feel closer to reality than other games where your attention is on the cars and road ahead of you. I imagine folk will argue a lot over that. In terms of overall ability to produce realistic shots though, it's no longer a case that the rest of the competition look cartoony/arcadey. GT actually has real competition and can't lay claim to being undisputed king of either visuals or race experience. Perhaps the only area it's still undisputed is selection of lounge music in menus (?).
Which, with GT being a generation behind, seems pretty obvious and expected! How much PD can achieve with GT7 is to be seen. The weakest aspect of any racing game's lighting is the direct sunlight situation. Overcast and wet and dark looks good on plenty of racers, but the sunlit sections aren't those other areas' equals and tend to reveal the limits of realtime graphics, especially in the scenery.