JDM von Weinberg , Jun 24, 2010; 07:19 p.m.
If you stick with the 50D, I think that in the long run you'll come to prefer its control system to that of the "Rebels". However, there's no denying that you have been imprinted on the Rebel system, so at first the more extensive system will seem awkward.
Depending on what modes you are using to shoot, the images on the 50D may well have less "zap" than the Rebel. Most people consider that the Rebels (and certain other whole brands of camera) are a little too "poppy". Sort of the way people will prefer a hamburger with lots of sugar in it when they are not told it is sugared.
You can go into the settings and parameters and make the 50D 'zippier,' but look at the colors more critically, and see if you don't think the slightly more muted tones are actually closer to nature. Contrast and saturation are not innate qualities of the pictures you take so much as they are variables you can manipulate for the results you personally prefer.
Questions like which color space you're using and whether you're shooting RAW or not are also things that can make differences in perceived image character.