if we compare 400d with d40x? which is better?
for canon the motor has always been in the lens, so it's not an issue.
for the D40, the removal of the camera lens motor is a problem as you realise you can't use a lot of 3rd part lenses and so the cost is a lot higher.
I would compare the 400D with a D50 or even a D80.
the D40 is a step backwards. the only plus point would be that they've moved on to SD cards.
there is a reason why they renamed the D60 a D40.