Does it matter whether I put a MY_model.php into libraries/ or core/ ?

[eluser]snifty[/eluser]
I'm a bit confused about which is the best practice. I want to use a base model, and I've found various forks of one called codeigniter-base-model on github.

But the READMEs differ:

https://github.com/notomato/codeigniter-base-model says to put it in application/libraries.

https://github.com/jamierumbelow/codeigniter-base-model says to put it in application/core.

Is this just a matter of preference?

(I suspect it would be better to do this with a Spark, but I've had trouble with my curl's HTTPS support. ).

Thanks!