I got a free 618 as part of a giveaway contest. The 618 is the 601 with carto tank (maybe the same as the 601-C with a new model number, maybe an upgraded model, unsure).
2 weeks? Mine died within around 30 -puffs-. And every single puff tasted like plastic (and before I washed the parts it tasted like plastic and machine oil). And it is a POS when it comes to how the cap screws on/off and the cheap metal battery arm inside. Oh and the red LED that lights the cap worked for about 4 puffs and never activated again.
Save up the money for a "real" pipe (ePipeMods, JazzCarto, etc etc) or put the money towards a nice non-pipe mod or high end traditional ecigarette.
These things wholesale from China for $25-30 depending on qty ... resold through middlemen for $40-60 ... then retailed to you for $76-100. TOTAL waste of money. I'm currently using the carto+tank+mouthpiece on a different battery just to sample a new
juice flavor and at least the carto isn't total crap ... but I'd be ...... if I'd paid anything for it. The tank does not disassemble and the ends of the poly are already cracking (and it isn't my juice, all of my juices are mild).