While I understand the feeling that a decent is an evolving product, I think in reality that is a good thing. A lot of the improvements are software based, so you benefit from these if you have a machine, rather than it just being stuck at whatever version you bought. When it first came out it only did pressure profiling, and now it can do flow rate profiling and this upgrade is free.
In terms of longevity I don’t see any reason to be concerned. They seem to be one of the most transparent companies out there. All of the spare parts are easily available from their website from the most advanced down to a simple screw (see https://decentespresso.com/parts). They also provide their software open source, so it would still be around even if the company went bust.
I would agree on longevity if you were considering a “dumb” machine, but the machines being discussed here are all very advanced ones, so they will all contain a computer and many sensors.
I would go for the one that best fits your needs and situation. They all look like great machines.
