I'm actually surprised that so many people still think the x box is efficient for fight caves. As someone who used an xbow to get 5 or 6 capes and Rune C Bow for 10+ capes I can tell you with an educated opinion that the Rune C Bow BLOWS the xbow out of the water, it's not even that close.
Most likely depends on how much you wanna spend, cause you could just get a rune cbow with like the best bolts (dbolts e) or if you cant get the best bolts, you would most likely want to stick with karils.