Yes and no - there are people that work like this, but a lot of people don't. "Within DoF" doesn't mean sharp, especially not if important image elements are rather close to the DoF limits and therefore visible less sharp than other objects. Today's AF cameras are so good, I always prefer to focus on the main objects in the picture (visual "entry points" for the viewer) insted of setting DoF the way you do. If I can't focus on the main objects directly (like for example in street photography), I prefer foscusing on a substitute at a similar distance before recomposing and taking the shot.Only if you have to focus through the camera and then read the DOF
scale. With wide lenses it's pretty easy to look at scene, say "I
need 5 ft -- 10 ft", and dial it in without ever looking through
the finder. Great for street shooting--limited (or even zero) time
with the camera at eye level makes you a lot less obtrusive.
But there are many focusing approaches out there, all of them have their advantages and disadvanatges.
With DEP, you can factor in custom COC by metering a larger DoF than you actually need, no problem.DEP is also useless if you need a different print size--and thus
COC--than the "standard". With a good DOF scale you can just shoot
a stop or two down from the indicated stop. Doing this with DEP
would require a lot of juggling. There's no reason they couldn't
make this easy--a personal function or something--but they haven't.