As a very frequest flyer I always try to get an isle seat so I can get up and move around. The down side is you do have other people trying to climb over you.

The inside of a modern a/c is pressurised at the equivalent of 8000 feet above sea level. They cannot make it sea level as the body of the a/c would then have to be made very heavy.

Being at a non sea level altitude cause the body to loose fluid more quickly so drink plenty of water. The effects of alchohol are increased by the loss of atmosheric pressure, so lay of too many drinks.

I agree with the no sleep on arrival unless you are actually arriving at a reaonable time of the evening.