It's the new Shimano Ultegra 6800 and it's causing a stir. This updated front derailleur features the same technology as the pro-level Dura-ace. Like Di2 front derailleurs the mechanical braze-on version of the FD-6800 has a new 2mm hex support bolt that stabilizes the front derailleur against the frame by providing an extra contact point. The FD-6800 also has a trim feature so it can be fine-tuned to be quiet in all gear combinations.
New, longer pull arm for more direct and easy shifting
More equal shifting effort across the range
New support bolt for more stable contact to the frame