First I proudly declare that I am another Canon guy.
IMO there are a few aspects to it. Try the camera in your hand and feel them, however, if you prefer one over the other it is not quite the end of the story.
It's actually more that D80 vs XTi. When you are buying an SLR system you don't just stop buying at kit lens. It's just like it's rare for people here to buy a 20G, a pair of clownfish, some dead corals, fluorescent light and an airstone skimmer and stop there.
You should consider the system as a whole, each has its own strength and specialty. For example:
- Nikon flash system is generally considered more consistent
- Canon is generally considered to have better high ISO performance
- Canon has more USM lenses than Nikon has their AF-S lenses, especially prime lenses
- Canon has more lenses in white, if that matters to you
- Nikon body especially at entry level tend to have better build than Canon
- Nikon macro lenses options are generally considered superior, you have 105 mm macro with VR, Canon's 100 mm macro doesn't comes with IS, Nikon 60 mm does 1:1 and Canon's 50 mm does only to 1:2, Canon has a new EF-S 60 mm that does 1:1 but it only work with 1.6x crop camera
- Nikon wider lenses seems to be stronger than Canon's
- Canon has more long lenses
- Canon has full frame bodies, Nikon takes forever to launch them.
- Canon tend to update their model faster than Nikon
- Nikon kit lenses are generally considered better than Canon's
When I say one is better than the other in any of the aspect, I don't mean that that other brand's aspect is bad. Both are reputable systems that has survived decades of competition. By identifying what will you be using the camera for is a good first step.
