It's different because The Matterhorn is actually the same (or pretty similar) as the WDW Space Mountain. They built Space Mountain in MK based on The Matterhorn ride system, hence the single row "bobsled" style seating. Space was popular, but they couldn't just build another Marterhorn at DL plus they didn't have the space so they went with a new design with a smaller footprint. It's debatable which one is "better" but the actual ride at DL is probably superior. I still prefer the MK version though for it's larger scale and entrance tunnel, etc.