Most bicycle tourers out there, are strongly against the idea of a light carbon touring bike, and touring with an electronic groupset (Ultegra Di2). Although I agree that it is not the best choice for all tours. In this thread I all post my story and experience about touring with such a bike.
A couple of months ago I started built up a Carbon cyclocross bike(carbon everything down to the seat post clamp, and steerer tube spacers) with Hydraulic brakes disc brakes and Ultegra Di2 groupset, with a 50/34 crank, and 11-32 cassette. The frame I purchased from online from ICAN bikes, I picked this frame since it had mudguard mounts, and was completely carbon fibre.
My intent for this bike is not to be a short weekend ultralight road tourer, I will be using it for a 4000km (2500miles) international unsupported tour, I will be giving up my comforts either, I intend to take things like my dual skin free standing dome tent, tablet, winter gear for 0°C (32°F), and a whole lot more, all carried in custom made bike packing style bags.
Some time during this week or next week, I will find time to take and upload a photo of the completed bike. I will be going on a number of trial weekend tours, and the major tour in Nov-Jan (No fixed dates yet) I will post about my experiences on it, speeds, distances, about the gear I take, and the bike bags I have yet to make(I really mean get my wife to sew them)