We log every dive ... mostly ...
Logbooks can be great learning tools. Once yur lernd, no need to log as much.
When we started out we wrote tons of stuff. We also would pull out the dive log and reminisce once we got home. That got old.
We then graduated to putting both of us on the same dive log page (custom excel spreadsheet printout) that provided a space for me to draw the contour of the dive site. That got old (I dove one dive site 13 times this trip, I do NOT need to draw it again...).
What we have found useful over the years are:
- how much weight was I using last trip?
- which fish did we see on the trip?
- how much bottom time did we ring up?
- what was my dive profile like? did I bop up and down too much? where my ascents fast-ish?
We now have a 3 way split log book:
1) a double sided piece of paper with many lists of fish & creatures with a "few", "some", "many", "juvenile" checkbox that we look at each day
2) our old 2 person per page log that we only really fill in bottom time several days later and ignore the rest
3) an electronic download into a PalmPilot from our bag full of Uwatec Aladins (yes really, Palm lives on!)
Our paper log has spots for air in and air out and lots of other stuff (wind, current, weather, ...) but we now ignore that as this stuff has become well known since we tend to repeat a lot (Bonaire, T&C, Belize, Bonaire,...)
As critter finders and lazy butts, we now tend to fixate on what we have seen and how much bottom time did I get.
And to answer the OP question:
As a vacation diver, I can not remember the last time I saw someone filling out a log book. ours is done in the hotel room, but on a liveaboard we often do it in the salon. I can also not remember seeing anyone looking at tables, or using their dive computer to plan the next dive. My impression is that most vacation divers are oblivious.