SQ, its no contest
I just flew SQ34 SIN-SFO in PE a few hours ago. And Singapore to Australia in Y with 3 empty seats across a few weeks back.
i could not get any meaningful sleep in “poor man’s lie-flat”, no matter how many positions I tried (And I’m only 5’10’’/176cm). Just now I actually managed to get semi-comfortable. Same for JFK-SIN on the nonstop flight in PE a few months back.
Now, I’m not saying SQ’s PE is comparable to business, but it is vastly better than most airlines’ PE product, and I would take it over Y - even a whole row of it - any time.
Coupled with the infinitely better service you get in SQ vs UA, it’s a no-contest for me. You’d literally have to pay me to fly UA instead.