Although I still use it (with Linux) and have a couple of top-spec daily drivers, I feel it's a matter of time it will "join the bleedin' choir invisible". Which modern laptop will provide a similar feel, weight and size?
It doesn't need to be Apple, of course and lower end specs (RAM, CPU) are fine too, since I'll use it mostly for light work.
It still does everything I want it to do and is fast enough --even for graphics work. I'm stuck with OSX Mojave but don't feel I'm missing out on anything by not upgrading, as OSX seems to add more useless bloat with every new version. Even then I've had to strip out a load of crap from Mojave that I never use.
The only thing lacking is the battery, which has been showing 'Service Battery' since forever and doesn't last very long. But, as I use the laptop plugged in all the time, that's no biggy. If Apple did sell genuine replacement batteries to the public, I'd buy one and fit it. But it's not worth the risk to stick a third party no-brand copy in there.