I just want to comment on the durability of an X2 battery. While I haven't owned it for much over a week, it has proven to be pretty durable to me.
Yesterday wasn't one of my better days. I was making marinara sauce for dinner, manacotti, and realized I had forgotten to add fresh, sauteed garlic. So I sighed, broke out another skillet, diced and sauteed some up. I was vaping with an X2, 650 mah, clearo and RY4 the whole time. When the garlic was ready I picked up the skillet to scrape it into my pot of sauce which was simmering away very nicely at this point. At the same time I took a drag off the X2 and when I let up it fell out of my mouth (Yeah, the exact reason I normally use 78mm batteries when my hands are busy, but the X2/clearo/RY4 are soooo good). Anyhow, the X2 dropped, hit the edge of the stove charger cap down, bounced up in the air, completely clearing the top of my sauce pan, and landed with a "plop" horizontially right in the middle of my sauce sitting on the front burner! It didn't go completely under, my sauce is really thick, but it was easily half submuerged in simmering marinara. After a few choice words, I gritted my teeth, reached in a grabbed it with my fingers stinging. I wiped it down with a damp sponge, then a clean paper towel. I should have taken the tip off and rinsed it because the first drag tasted like a mix of marinara, garlic and RY4 (maybe a new flavor choice?), but other than that it just kept right on going. In the mean time the simmering sauce increased in temperature and splashed all over the stove to add to the splash from the X2. Just one of those days I guess. Oh, I did switch back to a 78mm for the rest of my cooking chores.