Two weeks ago, I got a MacBook Pro 16-inch. I got the base model (M1 pro, 16GB). My previous machine was a loaded-up MBP 15-inch from 2019. Bottom line: it's been the most noticeable performance jump I've experienced since SSD disks.
The improvement is ridiculous. My previous MBP felt slow, and it often struggled to dispatch moderate loads. As a programmer, I typically run local server processes, some docker, and my editor, RubyMine, which is not particularly light. From time to time, you could notice how it became less responsive for many seconds, and things felt slow overall.
The change with the new MBP is night and day. It's always fast, and responsiveness is a constant. It's as if it didn't care what you throw at it: it will do it quickly and without you noticing a thing. Running tests faster is probably what has improved my development happiness the most, but the change is deeper than that. It's not a linear improvement you can capture with before/after numbers, it's more like a qualitative jump: it feels different.
The previous generation keyboard is a well-documented failure. Mine had the third iteration of the butterfly keyboard and, despite of barely using it, I hit the stuck-keys problem a couple of times. Also, something felt off when typing on it, due to barely noticing any feedback when pressing keys.
I am sure the previous low bar helps, but the new keyboard is fantastic. The feedback when you press keys feels... right. I use one of the new magic keyboards with touch id at home that feels equally good. I know praising these is probably blasphemy from a mechanical-keyboard geek point of view, but, well, I am not one of those.
The new MBP is uglier. Thicker, heavier, less stylized, it looks more like any other laptop out there. It's clear this was a tradeoff they embraced to fix all the structural problems for good, and I'm good with it, but it's a noticeable one.
Basecamp recommended us programmers to upgrade to an M1 because of the performance improvement, which would also be my advice to you, fellow programmer. If you are still in the Intel kingdom, consider visiting M1-land as soon as you can.