Unless i did the math wrong based on a post Ingo made, a cr2032 would only last about 300-500 days on a WPC CPU. An eBay China special CR2032 usually only has 50% capacity too. The RTC inside the ASIC is a power hog.

Another concern.... does the RTC keep proper time at 3.3v or do you need to change the resistor? The circuit was intended to be on 4.5v.

I might be bias but... NVRAM! =D

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WMS for about 1-2 years times stuffed SHIT quality 5101s into their MPUs. They are marked low power, but consume current like a 2101. System 7 era I believe it was. The PCD5101P data sheets indicates it consumes a crazy low amount of current and will hold the contents down to Vcc = 1v.

$6 mem cap vs $10 nvram. Still a no brainer value wise to me (again, im sure im bias =P). SUPERCAPs do fail too overtime. Gamatron daughter boards used a 1F super cap. It held a charge for only about two hours, granted it was 20 years old.

Supercap life expectancy...

"The real application lifetime of supercapacitors, also called "service life", "life expectancy" or "load life", can reach 10 to 15 years or more at room temperature. Such long periods cannot be tested by manufacturers. Hence, they specify the expected capacitor lifetime at the maximum temperature and voltage conditions. The results are specified in datasheets using the notation "tested time (hours)/max. temperature (°C)", such as "5000 h/65 °C". With this value and expressions derived from historical data, lifetimes can be estimated for lower temperature conditions."

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FM16W08 endurance at constant R/W at 1 mhz is like 180 years.