The Furious is the Nitrous' replacement. The precedant was the Fury cams. A lot of guys liked the Fury (I never had the pleasure) because it supposedly wasn't as aggressive and had a smoother draw cycle. It's nemisis is that it was not draw length adjustable. Thus, along came the Nitrous with adjustable module and hard wall---and speed.
The Furious is Martin's latest attempt to tone down the harsh draw cycle a bit and still give draw length adjustablity and a hard wall. Most target shooters like it.
To date I haven't had the pleasure of shooting a Furious either, although prior to my neck surgery last year I had a brand new one. I just never got a chance to shoot one arrow out of it. At the time I couldn't handle the mass weight nor could I draw 40# so I sold it. Maybe next year.