forget
"As a passenger am I right in thinking that high altitudes on the SP weren't that comfortable. I seem to remember ozone affecting nasal mechanics, certainly mine, - until some sort of anti ozone kit was fitted."
Absolutely! I had serious sinus problems after a 747SP Lufthansa flight from Frankfurt to Los Angeles. It was around a 14 hour trip and a passenger who smoked a very smelly Meerschaum pipe from post take off to pre touchdown didn't help!
I [upper deck SLF] complained about the smoke but was told Mr Meerschaum was a regular First Class Lufthansa traveller and I wasn't, so he won! That was my last 747SP flight because of the sinus problem.
ISTR FL 450 was quite a long section of the cruise altitude. Then Concorde's FL590/600 and in high pressure/normal humidity one stepped out feeling GREAT!!!!