I just flew economy in Fiji Air for my first flight (AKL - NAN), now in the Fiji Air lounge while I wait for my connection to SFO. While the Bubble Seat concept probably started as a reaction to Covid, now it is marketed as something to give you elbow space and more room. Which is also the reason I was considering it (agree completely with above points re empty seat not helping with virus circulation). I ended up not purchasing it as it was a half empty flight and I had a window seat with nobody next to me. Looking at the seat, I am 5' 8" and I *think* I would be able to lie flat if I had a row of 3 to myself, maybe bending my knees somewhat. However the Fiji Air aircraft is an A330-200 with a 2-4-2 configuration. I selected a aisle seat in an empty middle row, crossing my fingers that I will have the entire row of 4 to myself.

FWIW I asked in the lounge about upgrading to business class for my NAN-SFO connection and the offer was $1,400 USD which I turned down (since I have a halfway decent shot at getting an economy row to myself)