Thanks for all of the replies so far!
I'm transitioning from the high wing world and getting used to low wing tank changes every 30 minutes and calculating "estimating" fuel burn. To me, the process seems like an accurate guess as to how much fuel is remaining in each wing. Especially in the Piper Warrior I'm currently flying with less than modern systems. Anytime I'm near a calculated or indicated 5 gallons or so remaining in each tank, range anxiety really starts to set in due to the inexactness of it all.
I'm surprised that pilots generally can't or don't trust their fuel senders. Isn't that an inherent problem?
Having a fuel totalizer will be a huge improvement and will show with a high degree of accuracy TOTAL fuel onboard. But you still risk the chance of emptying a tank with inattention or bad math. Or getting low and possibly unporting a tank during critical phases of flight at the end of a mission.
I'm kinda talking myself into the CiES senders as I think this is a pretty important consideration. Doesn't mean that I would stop doing the calculations but would know with a much higher degree of confidence that my math checks with the gauges.
Biggest downside is definitely the cost. But maybe accurate fuel measurement is more important than some other option I had planned.
Another option I discovered are low fuel optic sensors. Anyone have experience with these or something similar?
https://www.aircraftextras.com/FuelSensor1.htm
If they work, they would also give you that extra layer of insurance that the math isn't suspect. And they are a significant cost savings over the CiES senders.
Choices, choices.