I've been using a Nikon D80 for about 5 or 6 years, primarily with 18 200 vr zoom and a 35mm dx prime. My primary subjects are landscape and travel. I don't make enlargements beyond 16x20".I'm trying to decide whether a move to d3100 or d5100 is worth the investment. I know the body would be lighter to carry, but would there also be a meaningful improvement in image quality? Reading ads and reviews only adds to my confusion. Any ideas?