It's been a full year since I picked up 2 LTwoo ER9 groupsets, both units are still holding up! I was tempted to upgrade to version 3, but my version 1 units are still working fine. I had a few early battery related hiccups, but that problem was remedied by using the recommended 14500 800mah 3.7v batteries and periodically cleaning the charging port with cotton swabs and rubbing alcohol. The only modifications I've done to my groupset was change out the stock jockey wheels to Ultegra wheels, which in my opinion should be the default configuration (11t upper and lower as opposed to 11t/12t).
With the V3 improvements, I would probably still choose this groupset even compared to the likes of 105 Di2 or SRAM AXS. I just like having replaceable battery flexibility, the use of any type of mineral oil brake calipers and I can run whichever cassette speeds of my liking. I know people have had varying levels of success, but my ER9 setups have survived their first year!
