They're different solutions to different problems. A Rekluse "auto-clutch" shines in low-speed poking through technical terrain. It relieves your clutch hand to fully grip the handle and lets you focus on lines and smooth power application on a bike that's pretty much impossible to stall. Personally I use a Clake one-light clutch but I've ridden my buddy's 500 EXC with a Rekluse and I can totally see the appeal. A quick-shifter is useless when you're picking through tight trails with rocks, roots and ruts because you never get out of 1st year and are otherwise clutching the whole time, which is why a Rekluse or light clutch are wonderful there. Conversely, Rekluses and light clutches don't offer much solution to wanting to blip quickly through gears during fast, smooth speed transitions. Make sense?