My mom got me back into photography when she picked up a D90. I started shooting with a D-Rebel. Recently she switched over to a D700. I'd call her an "Enthusiast." She shoots amateur stuff every weekend, and just got 2 shots in a local paper. I'm thinking of picking up a Canon 40D. Here's the thing. Mom claims that she gets MUCH better shots from her D700 than from the D90. I think that, considering her level, the only difference in image quality would come from either a better lens or the full frame sensor. Will a full frame sensor make an appreciable difference in terms of noise reduction? I know there's a whole deal with cropping and focal length. At what point does the full-frame sensor become financially practical (or necessary, or noticeable)?