The iStick suffers from a number of inherent flaws:
[*=1]the lack of step-down below battery voltage
[*=1]the unfortunate choice of PWM calibration in mean rather than RMS voltage
[*=1]the 510 connector, which has two problems---the soft metal that makes the threads vulnerable to permanent damage through cross-threading, and the use of a fixed positive pin that is neither spring-loaded nor otherwise adjustable.
Some criticisms, such as placement of the 510 connector near the edge of the top plate, putting the micro-usb jack for recharging on the bottom rather than on the side, and the fixed internal battery rather than a user-replaceable 18650 IMR, do not seem to me to qualify as flaws,
per se. Certain users may object to these and other features, but they were reasonable design choices to keep production costs and physical size to a minimum. Occasional non-firing on the first button press doesn't seem widespread, and longer battery life is more a wish than a criticism, since 2200mAh is actually quite good for a PV of this size and price.
In addition, we have reports from numerous disappointed users of malfunctions that have resulted in total failure of their iSticks. As a result, some of these users have soured on the iStick as a product and would not purchase another, which is understandable.
The reasons I like the iStick are simple---performance, size/ergonomics, and cost. All five of mine are in service and perform flawlessly so far for a modest cost---I paid an average of $24 each. The diminutive size of the iStick is perfect for me, and design of the box---with no sharp edges and one side rounded---makes holding it in my hand very comfortable. My pinkie naturally supports the bottom, and my thumb is perfectly aligned with the firing button. In other words, for me the iStick is a joy to use.
I use mainly Aspire BVC tanks---Mini Naut, CE5S, and K1, but also GS-H5T tanks with adjustable air flow and Kanger dual-coil heads (which I rebuild with single vertical coils). I've even succeeded at getting EVOD-style clearos to work, as long as I rebuild the heads at 2 ohms. Yes, I'm careful when threading tanks onto the 510 connectors, but only my oldest iStick got a little wonky, and that was solved with an adapter (either the eGo-to-510 or the 510 Tank Controller, depending on what topper I'm using that week). I don't feel a need to go above 9 eLeaf watts with anything and get a great vape.
That said, I have pre-ordered the Cloupor Mini 30W for $29.99. After all, the race for a better iStick has just begun...
I could name off a list of choice words for some of that early stuff I ran into like a disposable or one gimic brand that is advertised on the social networks and now a constant thorn in the side in your email inbox for free trial spam! They turn around once you become a member and overcharge for useless..... #($*$#!!! That's how that goes!
Now we're vaping at 20, 30 and 70 watts, going through 10, 15 or more ml per day. Our hardware is fantastic and efficient. Our coils are hot and vaporize our juices in an instant. But the better the gear, the more we vape, and the better our juices are absorbed, the higher the dangers... 
