Spin88, I agree that seat width is more important than pitch for people of average or below average height. But, based on seatguru, seat widths are as follows on the aircrafts used by the following airlines to a sampling of destinations in Asia:
UA 777: 17"
UA 787: 17.3"
SQ 350: 18"
SQ 777: 19"
ANA 787: 17.3"
Asiana 350: 18"
For the sake of comparison:
LH 380: 18.2" (but seat pitch is 31")
TK 777: 18"
Going from a UA 77x to SQ 77x is a 2" difference, which is significant. But going from a UA 787 to SQ 350 (as in the respective airline's SFO-SIN nonstops) is only a 0.7" difference.