Hi, As I start reading specs, Arcsaber 8DX and Nanospeed 6600 and Nanospeed 9000X are totally different. The most important thing is, after reading it, I have totally no clue on what they are trying to tell me, like stiff, medium blablabla. I am a 8DX user now, I want to get 6600 to switch around. I have used Nanospeed 2000 & 3000 and I feel pretty like it. My friend said 6600 is very powerful, so I want to try it.