Camera Upgrade Needed

Photographs are a necessity of life and of course, travelling.  Now some, I agree, we can do without.  Like the one of the hearty eater in his Speedo on a sandy beach or the 20 different-but-identical pictures of the same mountain scene.

I am currently using a Canon Powershot A590 and the size and ease of point and shoot camera, especially when traveling by motorcycle, is great.  I have been fairly happy with the photos the camera produces but with an upcoming trip next year through some of the most spectacular scenery in North America, it's time to finally pony up and invest in a decent DSLR.  I feel the need to do these future photos the justice they are so rumoured to be deserving of.

My research is convincing me to stay with the Canon name for a  number of reasons including the wide range of accessories available for this brand and my first choice is the Canon EOS Rebel XSi (450D):

However, budget is a factor, and that being said I am also considering its predecessor, the XTi:

There are a few new features on the XSi that are definately desirable, but being that this is my first official foray into the DSLR world, maybe they aren't as important right now.  The-Digital-Picture.com does a nice page that gives you the ability to look at photos taken by the different cameras for an immediate output comparison.

If anyone is using these cameras, I would love to hear your opinions...