When I used to travel excessively, sometimes with long layovers outside the UK, I found that all the hassles of airports - security and etc swallowed a lot of time. Once I settled in to a lounge for a while, I enjoyed reading books. Either real paper ones, or on an ipad.
The only time I went out of the airport was in HKG, which I already knew quite well. But I could not resist a couple of hours on the Peak. Coming back to the brilliant CX lounge, I did wonder whether or not I should have just stayed there............