The High Direct design was quickly embraced by frame manufacturers due to the fact is doesn't force a frame designer to compromise a rear suspension design due to the fact they have to figure out how and where to place the front derailleur. With a direct mount, the derailleur simply bolts onto the outside of the frame as opposed to having to wrap around the seatube. Originally brought to market by Shimano, it is now universally embraced. The High Direct is also being used on carbon hardtails do to the fact that it allows for a cleaner and stronger mounting platform.
Many riders comment on how quick and accurate the front shifting is on SRAM drivetrains are, giving most of the credit to the trigger shifters. The fact is the SRAM front derailleur does a lot of the heavy lifting. The oversize and super stiff bracket combined with a strong return spring manipulate the chain up and down the chainrings with ease. The XO offers a black anodized body with a treated cage for added durability.