I have the XTi (400 D ). and it is superb. It gives top quality results and has a spec that is better than most pro-spec DSLRs. Obviously it is a lighter build and it is also very small (I climb hills so this is EXACTLY what I was looking for). Easy and responsive to use.
Bad points..... er.... errr ...... well...... Must be something ....... somewhere.... Not found it yet though. Pick one up play with it. and form your own opinion. But in my mind you'll not get better 'til you pay 5 or 6 times as much.