I have both and the Virutex is a nice tool but its cutting width is less than the Festool. Although Festool state 2mm is the maximum for their tool I've occasionally used it on 3mm with no problem.
"Max. cutting width with 1 mm (3/64") thick tapes is 55 mm (2.2") wide
Max. cutting width with 2 mm (5/64") thick tapes is 45 mm (1.8") wide
Max. cutting width with 3 mm (1/8") thick tapes is 25 mm (1") wide