I have a highish cadence most of the time (85-100 rpm) but am not really bothered what it is at any given moment. I change gear when it feels right, which is when I sense the cadence dropping, or when the spinning gets silly.
I do not have a cadence sensor, and do not want one.
What I would like is an accurate 'rate of ascent' reading on my GPS. I discovered a RoA option on my Garmin on my last ride but it does not have a sensible averaging function. I would like it to show an average for (say) the last 15 seconds, but it jumps about all over the place even though my speed and the slope of the road are pretty constant.