We are doing premium economy to Lisbon/Madeira on TAP next month.
We booked economy to Singapore three years ago. Then a month prior to blast off we upgraded to business on a Untied offer ( our very least favorite airline for SE Asia). It was less than booking business in the first instance. 17/18 hour flight with lie down seats are so much better than economy.
We are getting old....70 this year. We switched to Jetstar Sydney-HML because it is a snap for us do do 10 hr. in economy or premium economy (sometimes the difference is more in the price than the seat so one needs to verify vs. assume). Two or three days in HNL then we do the last leg. We are hoping to spend the next winter in SE Asia...might be our last. It is time to book business.
For us it is three flights, 24 hours going to Thailand, 19 coming home It has been getting progressively tedious for us. We prefer Korean, then Delta. The flip side is two months on uncrowded beaches in Thailand, incredibly friendly locals, and wonderful food. It has been well worth the air trip for us. I think that we after next winter we may switch to Mexico or Costa Rica for winter travel.
One thing we both did after retirement was get is shape, get down to our recommended weight. I did lots of business travel. I found that travel, air in particular, was a lot easier after I dropped 40lbs and was in better physical shape.