Pack a day for 21 years. I took to vaping like a fish to water, not even any transition period required. I picked up my first PV, filled it with liquid, and never looked back. (Well, once, but that was related to a bad juice that I thought was some kind of reaction to vaping in general -- thankfully it wasn't and I went right back to vaping when I learned the truth.)
The thing about vaping, at least for me, is that it gave me everything I needed out of a cigarette and nothing I didn't. I still get my nicotine, I still get my much-needed throat hit, and I still get the ritualism -- the hand-to-mouth action I crave when my triggers kick in. Except now I get to vape at work.
So yes, for me, and for many, many,
many others, they work where no other method did or even could, and for me, the switch was as easy as switching brands -- easier, even, since I like this far more than any cigarette I've ever had.