You really shouldn't be getting internal leaks anymore. My unit has been totally dry for weeks now. Check the upper seal & make sure it's a good fit around the atty.
It's easy to over feed when the battery gets low. It'll seem like the atty is dry, but it's really a lack of power. Over feeding will still cause a leak, because the juice has to go somewhere.
It's true that it is easier to flood on a low battery, but when everything is right even that won't make it leak. I dunno, maybe I'm just lucky. But since I've gotten mine it's been in CONSTANT use and has had close to 100 ml fed through it. I haven't had a single drop leak in the chassis (or out). There have been times on a low battery that I've flooded it horribly and was sure I'd find the inside soaked, but when I took it apart.... not a drop. My buddy has been running his nonstop for 2 weeks now (his first PV) and also has never seen a drop of leakage.
I can see where if something is off it could cause leakage but the design is sound and I'm real world proof that when all is right it just *doesn't* leak. I'm sure those that have leakage have a simple problem (maybe not so simple to find, but when you do, it will be simple to fix). Don't lose hope, it's worth it to have such a hassle free vape!
Again, it could be that I'm just lucky (well, me AND my buddy). I have a second on the way. I guess we will see if lightning can strike three times!
And btw, the next one coming certainly won't be my last. I like to have 3 flavors always ready, plus a backup or two. I'm selling off everything else, despite the fact that all the others were much more expensive, because this thing is just THAT GOOD.