I have used several generations of Davinci vaporizers and have found them to be very reliable. Shipping is always fast. My most recent purchase was an IQ3. On the positive side, it heats up very rapidly, far faster than earlier models. Also, its battery does provide significantly more uses between charges. Especially in relation to the IQ/IQC, the vapor is much cooler and far more pleasant. On the negative side, the IQ3 is extremely large; when I use it, I feel like I ate the wrong mushroom in Wonderland and shrank. It also has an extremely large chamber, which seems unnecessary, especially since I had to run the pearl down most of the way for the IQC/IQ2 (i.e., this seems to mostly solve a nonexistant problem). Overall, I would prefer the IQ2 because it has most of the same cooling vapor benefits and was much lighter and smaller (easier to transport / conceal). The better battery life is nice, but doesn't outweigh the negatives of bulk and way too large chamber.