Do I keep a log? Yes. Do I log every dive? No. What I log has changed.  No longer keeping dive profiles, temps, gear used, pressures, etc. Now most are very short. Location, dive site, buddy, animals I see, favorite photos, and unique aspects of this dive. Most of the time that is all. Sometimes I will record information for the trip, Dive #, unique features or wreck names. I use it to jog my failing memory later for details I may need. 

My favorite thing to log are "Firsts".  Every trip there are still first experiences that I have never had before.  My Cuba log had a lot of them. First dive with a crocodile, first live aboard, first time in Cuba, etc. It is fun to re-live some of those experiences right there in my log.