I was able to heat up and use the unit for three sessions, and then the device never worked. Customer service sent me a battery, but the issue with the device was still not fixed. By no means is my story generalizable, and you will more than likely get a working device, so I think it is certainly worth purchasing, mainly because of the return policy. The return process was fantastic, and the turnaround was about two days. Also, customer service was excellent because they did not try to pull a used car salesmen's stunt and coerce me to keep the product, which I appreciate as an up-and-coming business, and I fully support this company and its future endeavors. The concept of the Hydrology 9 NX is exceedingly cool (mainly because of the concentrate feature), and even though I only got three sessions in, it was undoubtedly a different and great experience. I will undoubtedly try this vape again in the future, but with a newer, upgraded model.