First up: the Universal Monoextension. This bad boy will accept ANY standard 22.2mm extension without complaint, allowing easy reach and roll adjustment without moving any of the other components in the front end. I'm VERY MUCH in favor of this piece of hardware over any of the other Monoextension units. This is an aftermarket piece, but if you own a 2014 Speed Concept it's really in your best interest to spend the extra cash to buy it.
When I reviewed the New Trek Speed Concept, despite all the improvements and changes, I still had a few little nitpicks to offer. Perhaps the two biggest of these were the change in saddle clamp mechanism, and the fact that there was no compatibility with standard 22.2mm extensions. Well, leave it to Trek to continue development of their flagship bike, because both of those complaints have been completely solved. If you're bothered by either the seatpost or the extension mechanism, Trek has you covered. In this gallery, you can see detailed images of both of those solutions, as well as the unique BTA bottle cage, designed specifically for their Monoextension hardware.