Actually I ordered my VP9-B when that style first became available. I figured that since I was more accustomed to the button type release, I would just go with it. A few hours later the same day that I placed my order I changed my mind and switched to the paddle style. I figured that the paddle style was the more traditional HK style and decided to go with it.
As luck had it, the seller had already shipped the VP9-B. They said that they would catch the VP9-B at the FFL and have it returned and ship out the new VP9 paddle style. So when I went to pick up my VP9 at the FFL I had the unique opportunity to not only check out the paddle style, I also got to check out the B style.
I have to admit, the button style feels good. It's positioned exactly where it needs to be and works perfectly. For someone who is more accustomed to that style of magazine release, it would be a great choice. I chose to keep the paddle style. I have to admit that I sometimes go back and forth with my choice, but the paddle design is also great, and since I plan on adding more HK's to my collection (just added a 45C) I thought that it would be more fitting to keep the traditional style of magazine release. The more I use the paddle style release, the more I like it, but in truth both designs work great.
The B style does have the advantage of being more commonly used and requires no retraining, but it's something that you get used to pretty quickly.