My wife and I own a D40x...and I'm looking to buy another camera in the next few months. I really enjoy Nikon so far and would like to stick with it, but don't know what the differences are between various models. The quality of images from the D40x is great. I've recently learned how to use the majority of the functions of it with ease making all adjustments manually for each given shot and lighting situation. I always use RAW, so, I'm getting the maximum quality I possibly can since I am doing artistic photos. Is there a significant difference in the D40x and the D90? or another comparable version?