That seems odd since the All About Symbian review found that the N97 by far took the worst photos of the four camera phones they compared (N86, N82, N97, INNOV8) and it was easy to see in their comparison photos. Maybe your N86 is defective (something more than the processing alogrithm issue that GSMArena saw).
Anyway, how about sample pictures from the N97 and N86 of the same shot. It's hard to really see the difference you're talking about with the N97, when you just post one random image and don't take the same shot with the N86 to compare.