My bro started out using Kanger Protanks on his first mech. He hated the way those USB batteries had that 7-second(?) auto shutoff so he bought a mech, but stubbornly insisted that there was no reason for him to move to rebuildables. All it took was one 2 minute vape session with my Orchid V4 and he was mind-blown. He's now a convert with an Orchid V4. Disgusted with all the money he wasted on Protanks, miscellaneous clearos/cartos, he tried to go back and give that old hardware some love, but ended up throwing them all in the trash.
FWIW, Kanger heads are easy to rebuild. I've squeezed some 28 ga micro-coils in there that make decent vapor, 3x better than their stock coils anyway (which still isn't saying much next to an Orchid).