First, I'm a huge fan of the SVD, other than the issue with their firing buttons.
Second, I'm not a fangirl of what I'm about to mention, and I'm disappointed it's not VW, just VV, but I bought a used ProVari Mini on ECF for a reasonable price, and, as they say, it "Just Works".
I've also found, personally, that I can pump the voltage up a bit compared to with my SVD and not get a burnt taste, and OMG, the flavor!
The two mods use the same signal type, but the PWM on the ProVari is WAY higher frequency. I don't know if you've noticed on your SVD, but sometimes they buzz, or have a high-pitched hum when you're pressing the firing button. You don't get that with the ProVari.
ProVaris aren't as easy to carry around as SVDs are, so my hand gets a bit tired if I'm on a walk. Because of the telescoping tube, the SVD just rested in my loosely-held hand. I actually need to grip my ProVari to keep it from sliding out of my hand.
The new ProVari P3 is going to be VW, but it's also going to be close to $300, from what I've heard. As I said, I bought my 2.5 Mini on ECF for what I consider to be a great price, all things considered, including that I've already spent as much as I spent on it and more for three different SVDs. I'm not afraid that the ProVari will go belly-up.
Take that for what it's worth.