I can't comment specifically on the Fotokemika Varycon papers, but do have experience with using both the Ilford and Kodak variable contrast filter sets on a number of different papers. Results differ depending on the set used, though either can produce perfectly good results. The #2 filter from the Ilford set may deliver results comparable to the #3 filter from the Kodak set with some papers. This is not a problem, once you've fine tuned your workflow and gotten some experience with the tools you have on hand.