The data point i currently refer to the most is heart rate. After that cadance.
Typically i have the following bits of data on the display; Time, Speed, HR, Cad.
If i've got trip length turned on speed moves to where HR is and i get an ETA counter on the top of the screen. While useful it annoys the beep out of me that i loose at a glance access to my HR. Though failing that i've got the comp setup to start beeping it's little brains out if i go above or below min/max rates