My LL core for daily use just died last night.
I haven't been on this site in months (sorry!) and decided yesterday to check this thread because my o-rings were degrading slightly faster than I expected. (Probably completely my fault.) After checking the most recent pages, I didn't notice any mention of the o-rings, but I did see a few people mentioning cores starting to fail and reduction of glow at peak temperature. I had noticed my core not glowing quite as bright the past day and a half (I usually start heating it with the cap half-on) but it had been producing vapor fine and I suspected my batteries were finally degrading and put it out of my mind. I figured the o-ring problem was my fault for fiddling with the cap while it's at temp too often and closed my browser. I then decided to watch my empty core's coil heat up just for the hell of it, having used it less than 5 minutes prior. After about 10 seconds I started to worry. No glow, no heat. I tried 4 different batteries with full charge, unscrewed and re-screwed the core into the body, checked for switch interference... no results.
The coincidence stings but I'm not too upset, since the repair/replacement will be free. However, seeing multiple reports of cores of different types fail around the same time has got me a bit worried. I'm going to have to disagree with the corolla/sports car analogy; personally, I was sold on the Cera being reliable and durable above all else. I thought my batteries would need to be replaced at least once before the core. If it turns out cores will routinely fail after 6 months of my style of use, I may have to look into another solution for my LL vaporizing needs, as much as I hate to cut my losses here.