Mines flawless so far but I only own it for a week now and got to ride it twice. Motor is almost dead silent (heard stories of noisy motors out of the box), use it in Trail mostly with a cadence of around 80 - 90.
I could imagine Brose is constantly improving the motor and Spesh working on the software side. Brose is well known for mechatronics applications in the automotive industry and I would assume Spesh has an automotive industry style contract with them, which would mean Brose has to pay for every single motor which is swapped under warranty, so it would be in Brose's interest to make the motor better over time. And then there's the fact it's a German company, if their product would constantly fail, some guys at Brose would literally jump into a knife because of their hurt pride.
Bought in September 2020 and ride ca. 2000km without problems, motor runs still great.
I have now sold it and hope the new owner will enjoy it as much.
My 2018 carbon comp is still on its 1st motor. I ride in eco mostly, don’t hammer in turbo on big climbs, avoid deep water and clean gently. The bike has been a blessing and only reason I’d upgrade would be if the newest lighter rides had as much power. S as nd I won the lottery. I scored mine 2nd hand w/less than 500 mi. And consider it one of my best investments ever. Up there w/my ‘97 ford power stroke pick up.. $4500 w/carbon frame, wheels and Ohlins fork. Only regret is for my Scott Genius enduro pedal bike. She collects much dust these days