+1 that is a nice classification, which goes for a lot of devices actually.
I also have a slight impression that 3 tends to come with higher reliability and quality in general? Maybe not for mobile phones and other things where fashion sometimes rules highly over function or is at least very important (like in, ugh those ugly screwholes on your phone), but definitely for tools, audio/video gear etc. E.g. my first rotary hammer was pretty much unmaintainable and died soon. The second, higher end one came with a complete parts list + schematics of every single bit in there + easy to get and complete service manual. Didn't need it yet though. And the same story goes for all kinds of devices ranging for walkmans to oscilloscopes I owned.
My (now backup) scope is a Telequipment D83. It was manufactured in 1976 in London in the UK. It is fully discrete (no integrated circuits), has a full service manual that comes with it, has not had a single part replaced in its lifetime and has never missed a calibration. After 38 years the tube is less bright but that's about it. One of these:
I also have a slight impression that 3 tends to come with higher reliability and quality in general? Maybe not for mobile phones and other things where fashion sometimes rules highly over function or is at least very important (like in, ugh those ugly screwholes on your phone), but definitely for tools, audio/video gear etc. E.g. my first rotary hammer was pretty much unmaintainable and died soon. The second, higher end one came with a complete parts list + schematics of every single bit in there + easy to get and complete service manual. Didn't need it yet though. And the same story goes for all kinds of devices ranging for walkmans to oscilloscopes I owned.