I have an XT and the 2 year itch.
The choices: Canon Xsi or Canon 40D
Both offer DigicIII sensor tech. Many features found on the 40D are now available on the Xsi.
40D offers slightly more features, including 3200ISO, WB in Kelvin & faster frame rate.
40D has more rugged build but the double weight. More conspicuous and twice the size of the Xsi, which is smaller than the XT.
40D is still about $300 more than the Xsi.
My Dilemma? If I buy the Xsi (strong contender) I'm concerned that I will wish I'd gone for the higher ISO and other features. Yet don't really want to haul around a tank. I have a couple of good lenses that also weigh a fair bit but have trouble with camera shake since my hands are small.
If I had money to burn...
Users of the 40D/Xsi represent,. The reviews aren't enough.