I defer to both on the seat width.

But actually the 77G frequencies (CX138/139, CX100/10 after Oct) are the best in terms of hard product and time. If you're ex-HKG and a late-sleeper the CX101 can't be beat. You've time to wind down at the lounges, sleep a solid 6+ hours on the plane and arrive at a half-empty SYD.

My mum is an early sleeper, so CX161 is better for her. If I take it, I tend to be so drained I'm unsafe on the roads.

Coming back I either do CX100 or CX138 - CX101 if I don't need to eat dinner in Sydney and want a relaxing daytime flight back, CX138 if I do but it tends to drain me.

The execs like CX138.
My mum likes CX161 cos she rather eat dinner at home. Mum is a small woman but needs a flat bed.