I just got a 40d. It's my first dlsr.
I'm in love with it. In manual settings it's a bit difficult to get your head around, unless you have a good understanding of ISO, aperture etc.
But if you're willing to give it some time, you get the hang of it
It's really fast.
But as the others have said, it also is pretty heavy.. But i don't think that should be a factor that should deter you.