Starchild, I haven't been using the stardusts exclusively for the last five weeks. I've also been using various carto tanks, and more recently, mega dual coil cartos. Who knows, if I did use the four exclusively, they may have pooped out by now. I honestly don't know how long they're supposed to last.
A couple of my stardusts already have small cracking around the base and if it sits for awhile, some dampness starts to form around it, but nothing considerable.
Over all though, the stardusts have been trouble free and easy to use/ maintain. I like 'em, and for the price of a pack of cigs, I don't mind if it only lasts a week. I've actually been finding my stardusts on sale for like $3.50 each here and there. I still have two more that I haven't opened yet.
The thicker, 100% VG juice that you use in your stardusts could be pooping them out prematurely, but I don't know for sure. You could ask some of the vets around here. Good luck......