I'm still using my Mid-2014 MacBook Pro 13". I think I will upgrade to M1 (or M2 if I manage to wait) but only because<p>1) I don't see alternatives to the ridiculously inefficient JetBrains IDEe, which have become barely functional on this machine (really, come on, why do you need so many more resources to do exactly the same job that ran flawlessly 7 years ago?).<p>2) I can no longer install the newest Xcode due to disk space requirements (40-50GB for Xcode 12, not counting simulators and other essential tools) - I have no words here, I guess when you are Apple you just demand that the whole world adjusts itself to you).<p>I wish I didn't have to upgrade since I detest giving money to companies such as Apple and find them abhorrent, but I am not ready to leave the dev work yet.
If the 2015 works fine for you and you don't need more horsepower, I don't see a need to upgrade. That said, the M1 is a seriously impressive piece of engineering. It's fast and incredibly power-efficient.<p>The M1 MBP however is definitely not worth the extra money from the Air, imo. It has a brighter screen, marginally better speakers, and a touch bar. If you do want a pro, maybe wait for them to release a new 14/16" model later this year.