how do you gauge and judge "timing"?

Just more audiophile mumbo jumbo. Meaningless.

For those who don't have a sense of it it certainly is Meaningless.

Hmmm, haven't heard that one before. 

If you want to understand the terminology of high end audio. I recommend The Complete Guide to High End Audio by Robert Harley. It is the reference guide to high end audio. 

The way I judge is by listening to songs I know well and then decide if the system sound "right" 

Obviously lots of room here for interpretation however over time if you remain aware of these attributes you will become better at gauging, 

PRat, Pace Rhythm and Timing.

Heavily promoted by Naim Audio, gets your foot tapping.

Loved or hated, sacrifices detail.