I've owned/used hundreds of mods and the only ones i am confident of are my ProVaris but even one of those stopped working after only 3 years. :D
Generally i've had 'good luck' with Provape, Aspire, Sigelei, Eleaf.
'Bad luck' with Sigelei, Yihi, Joyetech, every no-brand CHEAP mod ever...
I have...