Since I started working on them in 2006, the goal was to add power without sacrificing the reliability of the NA zetec/conversion.
Right now people have to choose, although many don't realize what they are leaving on the table. Most people have the viewpoint that with a Bostig they are leaving power on the table, and they can get Bostig reliability with a subaru based conversion. In reality with a 2.5 Subie they are leaving reliability on the table, and with a 2.2 they are leaving both reliability along with no power advantage on the table.
The current turbo rev has been in testing since 2009. It is not dead. There have been 4 major revisions, non-intercooled, 2 air/water intercooled, and the air/air intercooled ones that have been running since 09. I don't like the turbo as a power adder for anyone. It has the upside of having upside. If you want to do a crazy build and make 400HP, you can, and break everything in your driveline as often as you want. But it has downsides in that its number of points of failure, modes of failure, and severity of outcome of failure are still such that not anyone can just run it and have it be reliabile, its compeltely subjective and varies by owner. That is not the solution that Vanagon owners need.
The alternative is the opposite, very few points of failure, very friendly modes of failure, and very low severity of outcome for even the most catastrophic modes of failure. Driving a syncro with 180HP and 200ft/lbs of torque that just keeps going and going is so great, more people need to experience it. I'd also like to help avoid more cases of the few unfortunate folks that inadvertently commit Subicide with a gremlin riddled setup after dumping ton's of money into the project to then perhaps scrap the whole idea of a van. People pull Subarus for Bostigs for reliability increases, they learned the hard way the extra 30HP wasn't worth the risks they didn't fully understand. People only pull Bostigs for more power. Like my original plan back in late 2004 called for, we need a good power adder. And I'm almost done.