A few scattered thoughts:

1. Ex Oficio - I love the underwear. drying is super fast- always wring it out a second time while wrapped in a towel. That'll remove almost all the moisture

2. synthetics - I usually find that wearing it on the plane isn't so comfortable - i tend to travel onboard with an old pair of underwear/undershirt that I end up tossing at the destination. i still like the feel of 100% cotton on me when i'm on the plane

3. sock liners - i've not enjoyed just wearing these - i also find them a bit slippery.