I have ~9100 miles on my 30 month old 10spd Di2 set up and have had to do a micro adjust of the cassette/RD chain position twice in that time for minor
noise from chain position. The battery got flaky at about 28 months, not holding a charge. I would expect a charged once/month Li battery to last
longer than that, we will see with batt II. External wiring done on first frame and this is a real dirt magnet. Cracked frame allowed transfer to frame
with internal wiring and this is much nicer. The very attractive 11-32 cassette/11spd compact option and the fact that the 9770 (10spd) brifters can be
software modded to 11spd means I can swap to this setup from the 11-28 I now have for ~4-500 but as I will need a new rear wheel it will run closer to
$750. FWIW I have seen 9770 brifters for under $200 as a clearance thing. The 'old' RD will be mounted on my recumbent. If you shop around you can
find a complete ultegra Di2 11spd groupo for ~$1100 or so about double what the mechanical groups costs. Don't ride one unless you are prepared for
the siren call of the electric shift, it is very addicting. As to battery charge, expect at least 600 miles out of a charge, I just top mine off the first of
each month, no big deal at all as the external battery tops off in 15-20 minutes.

The wireless SRAM is really attractive but clearly is a top end offering MSRP at $2200 with possible price online ~$1700 or so, this is ONLY the brifters and
RD/FD and battery charger not the complete groupo. Install is a piece of cake disregarding removal of old components.