After four months of use I've had not a single hiccup or misbehavior with it, none of the sudden stalls or "beachballing" I had every so often with TB when fetching/sending despite running my own mail server inside my home network, nor any crashes (which to be fair weren't common with TB). I get the impression that the developers tread more carefully with feature updates. I perceive it as starting up and getting to fetch/process faster. I also appreciate that it's about half the size, as they provide a dedicated Arm64 bundle instead of a "universal" Arm+x86 flavor.