I have a Shiv TT disc module and 12 spd Dura Ace on order to go with the AeroCoach bars. I decided to get the Shiv because I have pretty much maxed out my Speed Concept (and done well with it) without going into new cockpits, marginal gain level wheels etc. When I looked at what I was going to be spending on those items, it made sense (to me, anyway) to get a disc bike to future proof the investments rather than tie it to the rim brake Speed Concept.
Now just fretting over my wheel selections. I probably won’t see the Di2 for a long time, so I have plenty of time to examine all the marginal wheel gains.