The image on the left was taken with the Meade DSI in December 2004. The image on the right was taken last week with the Meade DSI Pro II.
For those of you not intimately familiar with how the Crab Nebula is supposed to look, let me just say that the image on the right is much better. The most obvious difference is the color. The older image is a uniform pale yellow-green, while the image on the right shows red tendrils of gas tangled in a blue-white cloud.
The improvement comes from using better equipment (the new DSI Pro II is more sensitive than the original DSI) and from spending more time capturing the image. The original image took one hour to capture; I spent almost three hours on the more recent one.
But the other difference is that my tastes have changed. When I first processed the original image in 2004 I thought it looked great! Now I notice the slightly elongated stars (evidence that I didn't track properly) and the dirty, not-quite-black background (from a lack of experience with processing techniques).
I hope that two years from now I will be similarly dissatisfied with the image on the right.