For those of you who like Di2/equivalents--more power to ya. Tinball's frustrations are the main reason I stick with simpler, time-tested components like mechanical shifting and rim brakes on my road bike: cheap to purchase, easy to install/repair, and proven to work for decades upon decades. As with everything, the more complicated/complex something is, the more that can go wrong. Not trying to start any trouble, just an observation.
Di2 actually isn't complicated. My frustration was from lack of knowledge and inexperience. Compared to wired shifting it's much easier to get get and keep great shifting. No bulky housing and wires to deal with. No wires to periodically replace or worry about breaking. Shifting doesn't go out unless you physically do something to the derailleurs.
I was unsure about Di2 until I got it. I wouldn't go back given the choice. I have the wireless unit so I have it paired to my Garmin and can easily monitor my battery level. If I had to guess, putting in 4-5 rides per week in season, I get about a month or just a bit less per charge but I generally don't like letting it get below 35% before charging. So it's no big deal in my opinion.
Disc brakes, I'll concede that I feel rim brakes are easier from a maintenance and adjustment standpoint. Stopping power and effort to stop goes in favor of discs however.
This build has been a learning curve for me from a few things. I have never actually had to run hydraulic lines so I was a bit nervous. But it wasn't all that bad except getting some experience on running the cables through the handle bar. Then getting the bars, fork, headset, and frame together with the lines. Difficult at first because of the lack of experience but was able to get it done.
Anyway thanks everyone in this thread for the feedback. Finally got the bike together. I had it checked out by the LBS just in case and got the all good on the build.
Here's the bike right before the first ride after work this week.