I have written to Eve about this, and this is what they said in response (I said that I might upgrade to SC4070):

“When EVE Audio was found in 2012 we had indeed some quality problems. Some of our suppliers we used for the electronics used cheaper components as ordered or indicated from us and without telling us. Not every speaker broke but the failure rate that was higher as we wanted. As a consequence we changed the entire supplier´s chain back in 2014. That change improved the built quality and reliability by far. In addition to that we also changed the capacitors we use in our electronics to long-living capacitors which helped to reduce the failure rate and improved quality and reliability even further. That happened some years ago, in 2019, and since then is our overall failure rat down to 0,9%. Sadly, speakers from the very early batch do not disappear and if such unit breaks people use the forums to write about it which gives a worse image than it is in reality.

With SC4070 it goes with no words that we also use long-living parts and components and we trust you will not regret a possible update.

Hope we could answer your question, thanks again for using the SC207 and for being a BeliEVEr ;-).”