Back a few months ago we had the opportunity to test and ride the Walzer Pintail. I absolutely loved that board. James liked it also, but as he practices more skateboard style tricks - specifically a shuvit, there weaknesses of the twin fin design become prevalent.
If you read the Shred Stixx ads of last year Jerry would point out that more fin area would equate to more drive. When compared to a single trailing fin, that is typical on say a Telum or 4skim...the thruster design of a Stixxstreme is significantly greater.
The Walzer design is a twin fin. It had more drive than a Prop, Telum, etc. and less than a Stixxstreme or F-18 in standard configurations.
What it gave up in drive, it gained in loosness of the tail. surface 3's were alost automatic.
The one drawback is that while the Walzer had an outline that would allow it to be ridden revert (tail first) the outboard location of the fins caused the inside fin to catch in the wave.
Here is a picture of the underside of the Walzer Pintail.
As you can see in the above picture, the fins are located fairly close to the rails of the board.