The X.7 promises performance and durability with the distinctive SRAM shifting prowess.
The 1:1 actuation is simply superior. The very nature of its design makes it this way. For every 1 unit of cable pulled or released, the derailleur moves the same amount. This is why the top athletes in the MTB world prefer SRAM. From the mud infested Cross-Country of the Sea Otter Classic, to the rocks and roots of a Fort William World Cup Downhill the 1:1 actuation stays precise and fluid. 1:1 Actuation precision is why you find SRAM on the elite bikes from cross-country flyers to full gravity bombers.
The Direct Route Technology has had SRAM singing the praises of this technology for years. Cut out the middleman, go direct, and speak to the actuation mechanism itself. Direct route technology is light, responsive, precise and impervious to cable housing damage. SRAM has simply reduced the friction by routing the cable directly to the actuation mechanism and less effort means you save the extra push for your ride.
Not the best installation process, and absolutely awful instructions. Once on, though, it sure does its job.