I got an authentic SVD from a US vendor and two days after the warranty ran out, it rolled off my table onto a carpeted floor (an 18" drop) and immediately after, the switch starting getting worse and worse over time. I can only fire it now if I let my thumbnail grow out and press really hard right in the center. What a POS. Until that happened it was the best PV I could imagine. Luckily, my vendor was nice enough to grant my request to take down the glowing review of it that I left on their site. Search this forum for pictures of the firing switch - it's a tiny little plastic thing, fragile as glass. Biggest waste of 50 bucks since I started vaping.
(Can you tell I'm still bitter about it? Oh yeah...)