I agree Best to a degree. Like you we installed a lot of Grant, I liked their boilers so much i chose to do my OFTEC through Grant in Wiltshire but even their boilers aren't invincible Riello burners are usually pretty bomb proof but we all know their pumps are c**p. If the system is installed correctly, flushed, dosed and regularly maintained and all points checked then yes its lifespan is vastly improved, however a lot of people install wrong or the customer doesn't have it routinely maintained, its swings and roundabouts.