Hi Dave,
I recently spent the day with a Nikon D90 and I have found the dynamic range to be really excellent, but I'm not a professional photographer and I don't want to pay that kind of money for a photo camera.Another problem I've had with the D90 was it's live view function. Eg. when you close the shutter on a compact you can see the image getting darker and when you take the photo it is a replica of what you were seeing on the lcd. On the D90 you could close the shutter, increase the iso, whatever and the image on the LCD with live view stayed the same. I'd like to have a DSLR with more or less the same dynamic range as the D90 and with a live view that works as "what you see is what you get". I've read many reviews saying contradictory things about the 450 XSI (some say the live view is awesome, some say it sucks, the same for dynamic range) so I'd really like to hear it from a user.