Here's what a review at Tire Rack has to say:

1985 Volkswagen Vanagon Camper  More Tire Reviews for This Vehicle    Buy/More Info
Continental VancoWinter
Miles driven on tires: 50
Location: STEAMBOAT SPRINGS, CO
Driving Condition: Combined Highway/City
Driving Style: Spirited

2 of 2 people found the following review helpful:

Initial Review, 50 Miles on Tires
January 08, 2007

2wd westfalia vanagon, with summer tires was USELESS in snow/ice- DANGEROUS. I got it stuck on the flat street in front of my house when backing up on pack snow w/ the summer vancos. These winter vancos change things COMPLETELY. Driving away from stop signs on 6" new snow over snowpack, up a 7% grade was just fine.  Driving around steamboat springs during blizzards was easy and safe with winter vancos.  The only slippage I noted was breaking on downgrades on polished ice at stopsigns.  I have not yet gone cross-country or over major passes during a blizzard with the new vanco winters, but around town these tires seem to be as good as the best "studless" I have ever used (incl. on my front wheel drive Jetta commuter car).  Still a bit lesser traction on polished snowpack/ice than studded tires though.

http://www.tirerack.com/survey/SurveyComments.jsp?additionalComments=y&commentStatus=P&tireMake=Continental&tireModel=VancoWinter