As far as i can see, they don't specify the capacitor material/type or value.
So, it's hard to say what sort of life you would get.
A typical electrolytic that i would pick would have a life of around 20,000hrs
That would include running at near maximum temperature (105C) for 50%
of it's working life. After that time the value would possibly deteriorate but
to be honest i've had the same old 6800uf cap on my t120 for around 20 years
that was one i'd had on the shelf for years as well. I can still start the bike
with just the cap and no battery
. I've never measured it's value, it was one
out of an old power supply i had.
They do vary in quality and specification though.