If you have both shoes (because you are asking which one to keep), would you perhaps care to do mod pics? I was thinking that maybe there is some deciding factor for one of them on *you*
Judging from shoe alone, I find the Viennana more "classy" (and yes, mary-janeish) and the Vortik more edgy (jeans, leather, more contemporary).
Aesthetically I prefer Viennana, but if I decided to buy a multi-strap style I would go with the edgier look, because otherwise it would be like craving ice cream but buying no-fat/no-sugar/no-milk substitute.