Flying SFO-NAN-HIR next week. Offered Bubble seat option. Traveling with spouse and we are last 4 seat row in middle on the plane. Behind us are 3 rows of 3. We each have the aisle seat. Plane doesn't look full... Is it worth the $400 to block the 2 other seats. I'm feeling its unlikely that someone will want to sit in the middle two seats. Would be nice to have extra room to get some sleep though. Decisions, decisions... appreciate your thoughts. Have never flown Fiji Airways.