Hi all!
I have recently purchased an used MacBook Pro 2012.
I have 16 GB RAM (OWC) from a Mac Mini 2011. From what I’ve read, it should work fine, but will I get better performance if I buy RAM specifically for the MBP 2012?
I can’t answer your RAM question, but as the owner of a mid-2012 MacBook Pro that has been my main machine for six years, I recommend doing yourself a big favor and upgrading the hard disk to an SSD. I did that about three years ago, and the difference in performance was just short of miraculous. (I had added 16 MB of RAM a year earlier and barely noticed the difference.)