I've ended up donating the few SMOK mods I had to friends that were trying to quit smoking. No big loss to me, and I figured if they were serious about vaping and hadn't moved on to another device when it broke, I would loan them one until they did.
Many folks don't have problems with SMOK devices. None of the ones I had ever quit on me, but they are definitely low on the quality end compared to many other devices available in the same, or even less expensive price range.
I have a few of their tanks that are for emergency use (no time to build anything), but I won't buy any of their devices these days. Why take a chance when there are better devices out there for less or equal money.