What camera?
Be prepared-- it's rather heavy as a walk-around. But if you're on a gripped camera, then weight shouldn't be your first concern I guess.
If your cam's full-frame or 1.3 crop, it's a perfect fit. If it's 1.6 crop, well, it's going to be a little too tight on the wide-angle side, and too wide on the telephoto side.
24-70 will be 38.4 - 112mm equivalent FOV on 1.6 crop cameras like your 40D.
To many people, 38-112mm is not wide enough, yet not telephoto enough. Neither here nor there. Like, you want to zoom out more than 24mm, but can't. You want to zoom in more at 70mm, but can't.
EFS 17-55 f/2.8IS is the highly recommended lens for 1.6 crop bodies.
And cheaper right!
I am assuming quality of L lens pics will still be better.... but zoom range not as ideal. Right?
What camera?
Be prepared-- it's rather heavy as a walk-around. But if you're on a gripped camera, then weight shouldn't be your first concern I guess.
The 17-55IS is said to beat the 24-70L in sharpness, but most probably not in color reproduction (without post-processing).
EFS 17-55 f/2.8IS is the highly recommended lens for 1.6 crop bodies.