I have used halides for the last 27 years continously in different setups, mostly Osrams and a few times Philips brand both 150w and 75 w. In the past I have always used the ones with the Quarz inner ball kind of part this ones always burned on me like clockwork after 12-16 months of use (lamp would start swithcing on-off-on... during the day) then it was time to change; now the new ones I've tried are the ones where this center ball thing is made from carbon and is cylinder shaped this ones have lasted for 2 years now with absolutely np (if there is a decrease in light I can't really tell), maybe it is the above that makes the difference maybe something else I don't really know.
By the way I never change bulbs until they are burned.
