the Ball claim of it lasting for 25yrs is technically correct, but misleading.
when 25yrs comes around, it will have 25% of the original brightness as the half-life is 12.5yrs, that would already be pretty useless in the dark.
even at 12.5yrs when it reaches 50%, i would think it would be pretty dim already and also kinda useless.
no Ball owner has experienced that yet, seeing as 2005 was when their first tritium model came out.