I love my endorphin speed, but I was looking for good shoes to switch between for marathon training. I chose this shoe because it's softer...perfect for recovery runs or when your feet are a bit sore. I wouldn't call this shoe "fast" and wouldn't wear it on race day, but it does make your foot feel secure. I don't feel the Speed Roller technology like the Endorphin Speed but I think it has to do with the 4mm difference. Overall this is another solid shoe from Saucony and will play an important role in my training regimen.