In the numerous trips to/from South Africa, crossing the equatorial zone at night - the turbulence is definetly less than it was even 20 years ago.
If you follow the flight on the skymap and watch the 'snail trail', you can often see where you have made a diversion and then back on track. Worst turbulence was a Viscount in a sub-tropical thunderstorm at FLO160 in 1971. Not good!
Then there was a DAK from JNB to WDH (Windhoek) just about everybody on that school trip was ill during the interminable flight.
An American boss of min ein the 1980s said that, when he was in the USSAF as an electrical engineer - they were testing new radar and to see how equipment under test would work in severe turbulence. So they WENT LOOKING FOR IT!!!!!!
He got the job of onboard test engineer as he was impervious to motion sickness and was perfectly happy studying the equipment - whilst being bucketed about! He was a nice guy and showed no other signs of madness.