The 30D is definitely built like a camera should be. It is very solid and features a magnesium body. The rubberized grip is very nice and one can easily fit their hand around it. Many consider this an upgrade from an XTi, but personally, I would not go from an XTi to a 30D. If I were to make an upgrade from an XTi, I would go to a 40D. The 30D's features are nice, but really the only things you get with the 30D that you don't get with the XTi is spot metering and a better build quality. However, the XTi also has some things that the 30D doesn't have such as: 10 megapixel sensor and a self cleaning unit. However, it might be better to start out with a 30D over an XTi. Overall, the 30D has all of the features you would want from a camera of this type.
Hope this helps!