I'm in NorCal and we get our share of smoke days. I have found that Purple Air is better for tracking air quality, I always use the LRAPA conversion, and generally I won't ride outside if it's over 150. But I have no particular lung/breathing issues.

The advantage of Purple Air over Airnow.gov, for me, is the sheer number of sensors. It allows me to determine where exactly the smoke plumes may be, how they may be moving, etc, and the data are in real time. A couple years ago, we used the data to revise a route for the Monthly C&V ride, heading North into clear air rather than our usual route, where the air was bad.