i really dont see that being the issue considering people run bigger power than you do and are not having the same issues. and you see how stock turbo cars get treated, they rarely get their filters changed by every day jane and jons...how much vacuum do you suspect is there when that filter is clogged to kingdom come? probably much more than your's and they still last quite a long time.

i vaguely remember the problems you had, but have you had any of these turbo's checked for balancing issues? when things shatter and bushings/bearings wear out very quickly, that is the 1st thing that comes to my mind.