I was pretty much the exact target market of the VP9. I was in the market for a polymer handgun for home/self defense in the sub $600 range...probably striker fired though all of my experience was with hammer fired guns. I was seriously considering the Glock 19/17, Smith and Wesson M&P 9, and the Walther PPQ. I knew of HKs reputation and read up on the HK45, USPs and especially P30s previously but never could justify one with my current financial constraints.
The VP9 put a HK into the realm of possibility for me. When I read the reviews and actually held it in my hands, that was it. Once I shot it I knew I made the right choice. I'm not 100% sure what I would've gotten if the VP9 wasn't available. I was leaning towards the PPQ but Glock has some advantages that are still pretty hard to ignore (aftermarket/accessories, simplicity in manual of arms, and track record). The VP9 wasn't even on my radar until I saw people comparing it to the PPQ. The VP9 got me to buy an HK when I never had seriously considered it before. I'd say thats a win for HK. And I'm sure ther are a lot of others like me.