Sliding guides are an acquired taste. They've been around for a LONG time and are common in the rest of the world. Their purpose is to have a rod "rigged and ready to go" in the smallest package possible. You can do the same thing with multi-piece rods, but it's not as easy.
I have two rods with the sliding guides. They are not JDM ultralight, though. They are both Euro float rods. I've landed carp well into the teens on the "light" one.