Agree with everything written above.
I also think most digital backs have a small shutter lag, at least my contact/phase does and it changes the rhythm in how we work.
A contax with film use to go click, click, click, with a p31 it goes push shutter, click, push shutter click. Not much of a difference but enough to throw you off if you've been shooting with film for years. You get used to it and the success rate goes up.
I think we just shoot more and faster. Digital is far from free, actually I believe if I count the costs of storage, processing time, computers, software, calibrators, monitors, etc. etc. etc., I know for a absolute fact that it costs me more per frame than film.
Regardless we shoot more and probably shoot some things we might not attempt with film.
Also it's just damn hard to read most lcds on any digital camera unless you use something like the 5d2 and live view, or you tether your digital back to a computer, running focus check all the time.
The last thing is we hand hold more. I don't know why we do this with digital when in the film days almost everything was shot with a tripod, but we do, so there is more room for error.
With medium format I've gone back to almost all tripod shooting and the focus rate goes up 10 fold, but given that sometimes things just look screwy. We'll shooting autofocus and boom one scene just doesn't go into focus, so I switch to manual and boom everything is fine, then 2 hours later everything flops.
Still, nothing improves focus like a tripod.