I had a medium Voyager, fully serrated, tanto point for years. That knife cut through ANYTHING, no matter how much abuse it sustained and without any sharpening. I cut through a thick rock climbing rope with it once, easily. With one stroke, it cut clean through with no resistance.
This knife was stolen, and I replaced it with a Large Voyager with the same blade style. I KNOW this knife will cut through anything I need it to, although I haven't used for anything yet. I have a Spyderco Calypso Jr. for a daily utility knife, and it works even better for small tasks and cutting sandwiches, etc.
My self-defense carry knife has been replaced by a Ruger SP-101 in .357 Magnum. However, when I need to walk the dog after having a couple of beers, my large tanto and a 2oz can of pepper spray accompany me in the park. I would NOT want to face any knife, but especially not that monster. The XL should be even more effective than the large.
~Ichiro