40D offers more versatility and control over the XSi. The XSi is an entry level camera, compared to the 40D, which sort of an entry level prosumer camera. Personally I have a 40D and I loveee it!
Originally Posted by ///M PWR 00
I just picked up a XSI with the canon 10-22mm and I am in love with this setup, I have been having a blast...
10-22 is a great lens. Quality is on par with L glasses