The machine we broke the arm on was a 725. It’s a rental, so I’m sure it was abused. The new CTX100 seems to have fixed that problem though, the older models had no support for the arms below the cylinders while the CTX100 has supports just above the bucket, so digging force is not applied only to the arms like the older versions.
The electronic problems have mostly been switch related, the latest was on a CTX100 where the switch under the foot plate was fluky. Sometimes it worked, sometimes it didn’t. When it didn’t, a couple jumping jacks would disengage the parking brake and it would work fine a while. My crew found it very entertaining to watch me jumping up and down all day.