His "Usecase OS X Linux Comment" table is interesting. My main workstation is a desktop machine I built that's running Ubuntu 14. I've been slowly stockpiling parts to build a new/bigger/better/faster desktop, and I'm going to run Ubuntu 16 on that. 90% of my work is done in the terminal, so I'd be just fine on OSX, but I can't justify paying so much for the hardware when the OS is just not that much better. My good ol' reliable 2009 PowerBook finally died and I'm not traveling with a ThinkPad Yoga 11e thing. Windows 10 has been acceptable, though the updates are just damn painful sometimes. I found MobaXterm works well for me in the way that I work. I keep thinking I really want a new PowerBook, but I just don't know why. I know it's just not worth it. The only time I use the laptop extensively is when I travel, and the ThinkPad/Windows gets the job done just fine.
So, yeah, switching from OSX to Linux now isn't so bad. Isn't 2017 the year of "Linux On The Desktop", or was that 2016, or 2015, or 14...
Any reason you aren't running Linux on the laptop?
Also, you might want to look into a used Macbook Pro. As you have seen, they can last for awhile and parts (like batteries) are usually easy to source even years after they've been discontinued. FYI, they stopped using the PowerBook naming in 2006.
So, yeah, switching from OSX to Linux now isn't so bad. Isn't 2017 the year of "Linux On The Desktop", or was that 2016, or 2015, or 14...