Here in the UK i have only seen them run 24/7 for a maximum of 4 years.

I would prefer programmed start ballasts for the fixtures that get a lot of on/off activity as well as short usage like what are on timers, but I am limited to what the facilities group orders, which are generally rapid start or instant start due to pricing.  I do however have faith that I'll be able to swing them over to the programmed start for special cases, and then rapid start for the rest, and to do away with instant start altogether. 

I remember at my old factory there were several 6 and 4 foot flouros in the rectifier house and they only seemed to switched off twice a yeari hardly ever saw a tube being changed the fittings rusted out before the tubes were knackered