I've got nothing against non-electronic index-shifters, but they do require more adjustment than Di2 systems (not a big deal - usually just use the barrel adjus

I've got nothing against non-electronic index-shifters, but they do require more adjustment than Di2 systems (not a big deal - usually just use the barrel adjuster). There's also the need to replace the inner cable which most people don't bother doing (I had one snap in the brifter head which seemed to be a fault with that particular brifter model). You can take my double-chainring when you can pry it out of my cold dead hands. I do agree about the simplicity and maintenance benefits of manual shifters (I do most of my own bike maintenance, so have worked on both systems) and if I were planning a cross-continent bike ride, I think mechanical shifters would be beneficial as it may not be easy to source electronic shifting components (e.g. hitting a rear derailleur on a rock and requiring a replacement). However, the sheer pleasure of using electronic shifting (a slight press and then a satisfying click-whirr to change gear) means that most people who have experienced it are unlikely to go back to mechanical. By the way, you usually just charge up the Di2 system rather than replacing the battery. Battery replacement is only for when something has gone wrong or you require features not supported on the older versions (e.g. synchro-shifting wasn't supported on the older external battery compared to the seat-post battery versions).