Please consider donating to help offset our high running costs.
Glock is a nylon-based proprietary polymer. All plastics are polymers but not all polymers are plastic. Not the same. 👍

how valuable is this distinction between plastic and polymer?

Very! Every time someone mentions the Speedmaster's plastic brake (blocking lever), inevitably someone says "it's not plastic, it's polymer!" 😉
What does Omega call it?
72208601726V2 | PLASTIC BLOCKING LEVER
Next someone will say "But it's Delrin!" like it's some magical material.![]()
The quartz crisis/the 90s did some awful things to many manufacturers unfortunately. Omega lowered quality of the movements of course, but they stayed pretty decent. Some manufacturers went completely out of business, many reduced their movement quality a bunch, and some, basically all the way. Tissot basically became a knock-off-timex-quality for a while.
My fairly recent example: Longines. They are typically my favorite watches to work on, some have been by far the highest quality feeling movements/prettiest movements I've worked on, even more than Omega and Rolex. However, I dug into a 90s Longines not long ago, and while it is better than the Tissot in OP, I was shocked with how cheaply made/awful it was (the 890.1 movement IIRC?).