Usually it's not an issue, but I'm thinking of that one night where we're on gravel and the weather is clear enough to sleep under the stars...
Ah, but maybe you're right. I figured the foam pad would be between 3 and 5 ounces, and multiple use as an instant nap whenever I wanted one without having to blow up the X-therm. That's almost worth it's weight in gold. I might just defer to the Z-light and leave the air pad for winter.
Edit: I should clarify. My modus operandus is to hammock camp, with the exception of nice summits and beaches where it's cold enough that you don't have bugs. Then I sleep under the stars. It is most excellent and often worth having a lightweight throw-around mat to take with you when you do it.
It's not something I'd carry all the time.