There's never been any good reason to have one. The only thing they do is help bring the pads toward the rim more evenly, which tends to give the brake more bite and a better feel. However in trials hold is more important, which the splitter has 0 effect on. On the downside, you have the initial cost, extra weight, more places your break can leak from, very fiddly to set up, harder to bleed and in the case your having it's probably easier to damage. I personally wouldn't bother with another, however, if your hoses are all set up for one it might be easier, than to re rout your hosing.