40 hrs in 1983 from cameroon to dfw....started w/ 8 hr drive to airport wait, then southern france-paris-lon -dfw....lots of seat time, all in the back, but some y seats weren't too bad, even for 6 ft 3 in....
i've spent 3+ days on a train in seats 6 or more times.....maybe getting close to 100 hrs sans sack....