I'm just going to share some thoughts, though not a review of the SMOK Stick Prince. I did a lot of research before I bought one and while reviewers generally gave it okay feedback, there are many, many negative comments on youtube about it which would seem to put people off. The reviews cover all the general aspects of the unit, so no use going into that. All the reviewers though assert that the device will get around half a day of usage. Now that I've had mine for a bit of time, I can say from experience over the holidays that the unit simply hasn't stopped from morning 'till midnight anytime. Obviously one reviewer said it and the rest just parroted off the same info. Likewise they say that it starts off too powerful, then gradually loses power over the course of a day. I must say I don't actually notice that at all though technically it makes sense.
A lot of comments suggested that coil life seemed to be a couple of days if you're lucky. Aside from the possibility that you can always run into a bad coil, I haven't seen that. Even after running a few weeks off one coil and changing it out, it didn't taste or operate any differently, it just goes and goes, this is using the default coil type that comes with the unit.
Another common theme you can see from lots of comments is the leakiness. Mine does not leak. At all. I assemble from the bottom up, and tighten it all really tight, and I mean really tight. Someone posted a comment about filling which I don't know if it's right or not, but I use it anyway. Close the vent, fill, turn upside down, then open the vent, wait 5 seconds, then you're good to go. He reckons it's something about making a vacuum, once again, not sure how well this theory flies, but for 5 seconds of my time it's not like he's got me standing on my head or something.
You also see videos and comments about having to use tricks to make it close properly. Mine closes solidly, every single time. The exception is if the filler nozzle pulls the seal up and it doesn't want to close, but you're alerted to that pretty quickly and it happens rarely. I even did an unexpected break test on mine from hip height to tiles, it banged and clanked (no rubber guard on the glass), and the crooked look of things made my heart sink. It was just the mouthpiece that popped out a bit and after straightening that out there's no signs of cracks or any other damage, maybe I was just lucky, but I did read the glass bit is some toughened stuff now, not sure, but not really willing to test it out again if I can avoid it.
So those are the thoughts of a complete newbie who went straight from an Endura T20 to this unit for an entry into the DTL experience. I make my own liquids, so I noted I had to reduce nic levels to account for the whole higher cloud factor and also note that I definitely go through a fair bit more liquid - but when you make your own it's still really cheap. I approximate that I mix 6mg because I had to take my existing 12mg mix and basically mix in half by volume VG, so everything is very roughly mixed until I get through the last of what I had and make a completely new batch. Now I've used the unit for a bit it does feel like I need to draw pretty heavily on it, so maybe that's the next upgrade to higher wattages etc. where the device can really make the cloudy stuff, that's where decisions probably get somewhat trickier.