From what I'm told they are about the same camera, just marketed differently around the world. I was also told the Kiss comes with a better lens. To combat the "gray market" Canon has given the same camera different names or designations.
JAPAN: EOS KISS DIGITAL X
AMERICA: EOS DIGITAL REBEL XTi
EUROPE, ASIA, OCEANIA: EOS 400D DIGITAL
A "gray market" camera (or lens) is one bought in another country with a better currency exchange rate and imported - legally - into a country where it can be sold for less than a camera imported by the licensed importer. So an importer buys cameras and lenses in Singapore, imports them into the USA and undersells ones imported by the USA affiliate of Canon, Nikon, etc.
Although this is legal, the consumer who buys a "Gray Market" camera or lens has no USA warranty protection. The warranty is only good where the camera or lens was originally sold. I cant speak about this camera specifically, but I will tell you that back in the day I bought an EOS A2. The non-US version was called the EOS 5. There were some minor differences in some of the custom functions and features. | 