I upgraded to the M1 air and it's the difference between night and day. The air on an M1 can do all my heavy development work no problems and I also don't have a loud fan anymore.

Ah, but this computer is a general-purpose home device that is mostly used for browsing and watching videos. The dev. stuff doesn't matter.

(And I no longer inflict my code on this world, only powerpoints!)

Bought a replacement battery battery for my wife's mid 2012 MBP. It was really slow even even after I upgraded RAM to 16GB and put in an SSD. Replacing the battery restored the performance.