Nothing against vape pens. Its just the market is flooded with vape pen companies who are very proactive in trying to sell their very similar products. I used to own a business (get high tour on a bus) and the vape pen companies would be sending ads constantly, got very annoying. I never had an ad saying, please look at my beautiful hand made glass done all by myself, its always look at my plastic/metal shit sourced from China.
Find me a vape pen and cartridge and I can make that fucker leak. Most of these super awesome best ever pens are made for liquid, PG or vegetable glycerine. Medical oils are much more viscous, but the vast majority of vape pens are for propylene glycol, not heavy oils. Don't bother asking if you can return it if it breaks, the answer is no. I started with Kanger but now I prefer a larger tank, and I have always had issues with bottom filled tanks leaking when there is any change in temperature/air pressure. Using small cartridges like o.pens or neos is that when the cart is attached to the battery, the valve opens, and leaks can happen. The only way to prevent leaks is to unscrew the tank from the battery every time you use it. I am far too lazy to do that, so I am still searching for a medical oil vape pen that isn't a piece of shit.
Most of this shit is for people who are trying to create large thick clouds of PG, not consume oil medically. The more potent the oil, the thicker it is, which means vaping can be difficult if the oil is too viscous.
I like the ease of use from eLeaf batteries, and I have been very happy with am isub APEX top-fill tank. I can burn through a 750mL cartridge between denver and the western slope, so a larger tank that doesn't require constant filling would be great. Or I could smoke less but come on. The isub tank allows for top fill, which is nice if you've ever had to move the liquid in the tank upside down to change the atomizer. The isub lets you change the atomizer from the bottom of the tank and you don't have to remove any oil in order to change the atomizer. Every other one I've used requires the tank to be low or empty before you can start changing out coils or atomizers.
I used to like o.pens 750mg refill syringes, but their strain specific PG laden crap doesn't test higher than 30-33%. I don't get how they can be strain specific but still have the same potency on a regular basis. I have been happy with Goldenbarn products, they claim to be raw, uncut, no PG, but high potency at about 70%. The question I have is how their products are so thin but are still 'uncut'. An email said something about putting the concentrate into a centrifuge to separate the filler or something but that sounded off.
I think the biggest issue is that these off-shore producers can't test anything with THC, so they make claims and see if they make it or not. I think what the vape-cloud-crowd wants is super high powered 'mod' batteries that burn through PG as quickly as possible, for the clouds man. Everyone knows dick size is directly related to the size of your vape cloud, and the exploding batteries are just collateral damage. The medical oil crowd just wants a product that doesn't fucking leak everywhere all the time. And by the crowd I mean me.