Now that I have had a bit more time with the Rebel T2i (550D) I can say that I am overall very pleased with it. I find the image quality to be very pleasing at the settings that I typically use (200-800).

The auto-focus is fast and accurate when using the center AF point (and when I select one of the other AF points) but overall I find the auto-select (9 AF points) function to be a bit lacking. My observation is that when I use the auto-select function AF performance doesn’t feel as snappy and the camera tends to grab objects in the background just like almost every other camera I have used. The other place where I observed some AF trouble was in back-lit situations (just like every other camera I have used).

The auto-ISO feature was something I was very interested in with the T2i and though I find it to be a big improvement over the version on the Rebel XS it still needs some work in my opinion. I like that you can now set the upper ISO limit but I would also like to some additional controls. For example in Av mode I would like to be able to set the upper and lower limits on the shutter speed. When I was using the camera with my EF 500mm f/4L IS USM and 1.4x II TC this wasn’t as much of an issue since the camera wanted a fairly fast shutter speed due to the long focal lengths. When I went to shoot flying birds there was plenty of shutter speed in auto-ISO mode. When I used my EF 400mm f/5.6L USM I found that the auto-ISO mode usually didn’t give me as much shutter speed for flight shots as I would have liked…

Overall I find the T2i to be a great camera. I wouldn’t choose it as my main wildlife camera over my 7D but it is an excellent choice for nature/wildlife photography and for me is an excellent back-up for my 7D or a great camera to bring out when I want to travel light.