>>1819063With Di2 every shift is flawless, derailers never go out of adjustment, cables never need replacing, auto trim is nice, and above all it means almost no effort is required at the shifter - you can sweep your entire cassette in either direction or shift between chainrings with a single press of your little finger.
>>1819084Sort of. Rim brakes are perfectly fine for road bikes, the vast, vast majority of the time the extra power of hydraulic discs simply isn't needed on the road even if it is nice to have. The real advantage of discs is that they allow for light carbon rims that don't require rim brake tracks.
>>1819221If you're riding because going fast and far is fun, then a bike that lets you go faster and farther is a fun thing even if you're not racing.
>>1819236>>1819229Sure, for threads where you're just looking to prevent corrosion it will do fine. I wouldn't necessarily use it in an application where torque is critical (e.g. bolts in a carbon stem) since I'm not sure how it will effect that, but for most things it would be fine.