One of the most important things I look at when buying a new APV is how dependable the device is. What is the track record of said device? How will it benefit me in my vaping journey? I am not a VV/VW tube guy and don't own any of these, but I have done some research and tried real hard to make a VV/VW tube type of APV fit in my collection, just hasn't per say happened yet... The only tube type APV out that is tried and true is the Provari. I am not sure of the original release date for the Provari, but I have been vaping for 2+ years now and they have been on version 2 for at least that duration and the only update for version 2.5 was a new body only!!! It serves the old adage, why fix it if it isn't broken...
All the others haven't been out long enough to be put in that class yet. Look at how many different versions or revisions of the Smok V/Z max's there are!!!! Sigelei, I think is on version 3 or 4 already and hasn't been on the market but 6-8 months now. The Vamo is only about 4 months and I think there releasing version 3 already!!! The eVic software has had 3 revisions also. I will say as far as all the new VV/VW units in general, I believe they all share the exact same SmokTech board inside now... I could be wrong on that, but I believe I read somewhere they do...
You might also take a look into some of the box type mods out there as well. Feeder mods are real popular as well. I myself vape a Vmod XL from Vapage and the REO bottom feeders are extremely well made and very popular. I switched to the Vmod as I was tired of carrying around an extra bottle of juice all day along with extra batteries. Now I just make sure the bottle is filled up, battery is fresh, and i'm good to go all day while i'm out and about. I also just recently purchased an all mechanical mod, The Natural, to go with the rebuildable atty's I bought to get back into dripping. I used to drip and drive for a living and is what lead me to the Vmod. Now when I am out and about or sitting at home I can still drip on the rebuildables. Nothing matches the flavor of dripping!!! This reason again, is why I chose a bottom feeder, other that the convenience of having juice on board and being able to use an atty... Not to mention it is pocketable while doing things...
Another thing I always took into account when looking for something new was the length of time and post count of people that recommended things.... Just remember you need to make the decision for yourself and try not to succumb to the, get this one or that one because of (insert almost anything here), responses you get from a lot of people here on the forum. Too many noobs today that have not tried multiple devices, are all too anxious to jump on the recommendation band wagon alll too quickly... And then when the 510 connector pops out of the unit/leaks or the wiring in the control head fries, or the board comes loose, or the window for the display cracks or comes loose, and on and on, the response is "I will just send it back to the vendor for a replacement", or if its out of warranty you see their next thread, "I finally broke down and bought a Provari"!!!!! That cracks me up... I have been through the journey of cig-alikes to eGo's to APV's, as well as carto's to cartridges, (yes their different!!), to tanks to atty's to rebuildables and on and on.... What a journey to say the least.... If I only knew then what I know now!!!
Sorry, I didn't mean for this to be so long...